Bioorganic & Medicinal Chemistry xxx (2016) xxx–xxx

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Synthesis and anti-tuberculosis activity of glycitylamines Hilary M. Corkran a,b, Emma M. Dangerfield a,b, Gregory W. Haslett a, Bridget L. Stocker a,b,⇑, Mattie S. M. Timmer a,⇑ a b

School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, 6140 Wellington, New Zealand Malaghan Institute of Medical Research, PO Box 7060, Wellington, New Zealand

a r t i c l e

i n f o

Article history: Received 26 October 2015 Revised 16 December 2015 Accepted 22 December 2015 Available online xxxx Keywords: Tuberculosis Carbohydrates Amines Synthesis Reductive amination

a b s t r a c t A series of glycitylamines, which were prepared in few steps from readily available carbohydrates, were tested for their ability to inhibit tuberculosis growth in an Alamar Blue BCG colourimetric assay. Several derivatives, including (2R,3R)-1-(hexadecylamine)pent-4-ene-2,3-diol, (2R,3R)-1-(hexadecylmethylamino)pent-4-ene-2,3-diol and 5-deoxy-5-hexadecylmethylamino-D-arabinitol, were prepared in good to excellent (44–90%) overall yield and exhibited micromolar (20–41 lM) inhibitory activity that was similar to the first line tuberculosis (TB) drug ethambutol (39 lM) in the same assay. The ease and low cost of the synthesis of the glycitylamines offers definite advantages for their use as potential TB drugs. Ó 2016 Elsevier Ltd. All rights reserved.

1. Introduction The treatment of infectious diseases that are predominantly endemic to developing countries requires simple medications that can be produced in large quantities at low cost. This is particularly true in the case of medications for the treatment of tuberculosis (TB), which is a disease that infects more than 9 million new people annually and which has a particularly high mortality rate for those living in developing nations.1 The treatment of TB requires an extensive period of drug administration and a cocktail of complementary drug treatments due to the persistence of the pathogen Mycobacterium tuberculosis (M. tuberculosis) inside host cells2 and increasing multi-drug resistant (MDR) or extreme drug resistant (XDR) strains of the disease.1 Current first-line drugs for TB include pyrazinamide (1), ethambutol (2), and isoniazid (3) (Fig. 1),3 and in addition to their obvious clinical efficacy, another advantage of these low molecular weight compounds is their ease of synthesis. Accordingly, we became interested in exploring the potential of small molecules as therapeutics for the TB so as to add to the arsenal of drugs that are required to combat this disease.4 Inspired by the simplicity of ethambutol (2), we thus sought to explore whether glycitylamines (e.g., 4, Fig. 2), or derivatives thereof, might also show promise in the treatment of TB. Moreover, as ethambutol (2) inhibits arabinosyl transferase (AraT),5,6 the ⇑ Corresponding authors. Tel.: +64 4 463 6529; fax: +64 4 463 5241. E-mail addresses: [email protected] (B.L. Stocker), mattie.timmer@vuw. ac.nz (M.S.M. Timmer).

enzyme responsible for linking the arabinose sugars to the arabinogalactan polysaccharide that forms a critical part of the cell wall of M. tuberculosis,7 there was also some merit in determining whether simple pryrrolidines (e.g., 5) showed promise as drugs for TB.8 To this end, we proposed that the glycitylamines could be readily prepared from their parent furanosides using our previously published reductive amination methodology,9 with the pyrrolidines then being synthesised from glycitylamines in two additional steps via carbamate annulation methodology.10–13 The ability of the compounds to inhibit the growth of BCG as a model for M. tuberculosis would then be explored4 so as to ascertain whether either of these two scaffolds would provide derivatives that show promise in the treatment of TB. 2. Results and discussion To commence our studies, we first undertook the synthesis of the readily accessible glycitylamines 4 and pryrrolidines 5 (Scheme 1) using our previously published protecting-group-free procedures.10,14,15 Accordingly, pentoses 6 underwent Fischer glycosylation with MeOH before the iodine was installed at the primary position. A Vasella reductive-amination, involving the use of Zn, NH4OAc (sat.), NH3 and NaCNBH3 in EtOH, then allowed for the selective formation of primary amines 4 (R = H),9 which were subjected to an I2-mediated carbamate annulation10 to give carbamates 7. Base-mediated hydrolysis then yielded pyrrolidines 5. By starting with different parent sugars, glycitylamines 4a–4d, pyrrolidines 5a–5d, and the corresponding carbamates 7a–7d were

http://dx.doi.org/10.1016/j.bmc.2015.12.036 0968-0896/Ó 2016 Elsevier Ltd. All rights reserved.

Please cite this article in press as: Corkran, H. M.; et al. Bioorg. Med. Chem. (2016), http://dx.doi.org/10.1016/j.bmc.2015.12.036

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H. M. Corkran et al. / Bioorg. Med. Chem. xxx (2016) xxx–xxx OH

O N

H N

NH2

N

HO

1

OH

O NHNH2

N H

3

Figure 1. Low molecular weight first-line drugs pyrazinamide (1), ethambutol (2), and isoniazid (3) for the treatment of M. tuberculosis.

OH

HO

OH

OH

HO

4b

4c

4d

> 3.5 mM

> 3.5 mM

> 3.5 mM

4

OMe

H N

Ph Ph

4e

OMe

0.44-0.88 mM HO

OH

HO

H N

HO

OH

6

OH

HO

HO

5

1.36-2.73 mM

HO

HO

H N

H N

HO

OH

HO

OH

5d

> 3.5 mM

> 3.5 mM

> 3.5 mM

> 3.5 mM

O O

O

O

O

N

O

N

N

N

NHR 3) Zn, NH4OAc NH3 , NaCNBH3 or Zn, R-NH2, NaCNBH3

NaOH OH

8

5c

OH

HO

OH

7a

OH

HO

> 3.5 mM

4

O

H N

Ph

Ph

4f

5b

O

1) MeOH, AcCl 2) I 2, PPh 3 , Imid.

I2 , NaHCO3 (where R = H) HO

H2 N

5a

O

OH

Ph

Ph

0.80-1.61 mM

H N

HO

O

H N

5

Figure 2. Glycitylamines I (X = H, OH; n = 1, 2) and pyrrolidines II to be tested for their ability to inhibit the growth of BCG.

HO

OH

4a

OH

H N

NH2

NH2

OH

> 3.5 mM

OH

HO

OH NH2

OH

OH

N

2

OH

NH2

NH2

HO

OH

7b

7c

> 3.5 mM

> 3.5 mM

HO

7d

OH

> 3.5 mM

Figure 3. Glycitylamines 4, pyrrolidines 5 and carbamates 7 tested for their ability to inhibit the growth of BCG in an Alamar Blue growth inhibition assay. MIC value determined as the concentration of drug required for 100% inhibition of bacterial growth.

O N HO

OH

7

Table 1 BCG Inhibitory activity of second library of glycitylamines 4

Scheme 1. Synthesis of glycitylamines 4 and pyrrolidines 5. Entry

prepared (Fig. 3), while the use of the secondary amine aminodiphenylmethane rather than NH3/NH4OAc gave glycitylamine 4e (R = Ph2CH). The use of methyl 5-deoxy-2,3-di-O-methyl-5iodo-a/b- D-xylofuranoside in the Vasella reductive amination with aminodiphenylmethane afforded the fully protected glycitylamine 4f. In this way, a first series of compounds was prepared and subsequently tested for their ability to inhibit growth of BCG in an Alamar Blue growth inhibition assay.4,16,17 As illustrated (Fig. 3), glycitylamines 4a–4d showed poor inhibitory activity, however the more hydrophobic derivatives 4e and 4f showed improved, albeit modest, activity, which was better than the MIC of diphenylmethylamine (8) alone. The pyrrolidines 5 and carbamates 7 showed disappointing inhibitory activity with MICs > 3.5 mM, which may be due to the hydrophilicity of the compounds and their inability to pass through the highly lipophilic mycobacterial cell wall.7 While modifications to an arabinose or related pyrrolidine scaffold may lead to inhibitors with improved activity, as has been demonstrated in studies by others,18 the sub-milimolar inhibitory activity of glycitylamines 4e and the ease of synthesis of these compounds promoted us to focus on the structure–activity relationship of these derivatives instead. To further explore the structure–activity relationship of the glycitylamines, we next investigated whether the stereochemistry of the diphenylmethylamine-functionalised derivatives influenced the inhibitory activity of these compounds. Accordingly, the growth inhibition activity of the arabinose derivatives 4e and 4f (entries 1 and 2, respectively, Table 1) was compared to the activity of the 2S,3R derivative 4g and the 2R,3R derivative 4h (entries 3 and 4), whereby the latter were prepared in 64% and 56% overall yield, respectively. Unfortunately, 4g and 4h showed no improvement in inhibitory activity compared to 4e and 4f. The activity of

Product OH

1

OH

H N

OMe

2

H N

OMe

MICb

60

0.44–0.88 mM

8

0.80–1.61 mM

64

1.6 mM

56

1.6 mM

57

NIc

55

NI

51

NI

25d

2.0 mM

60

940 lM

Ph Ph

4e

Yielda (%)

Ph Ph

4f OH

H N

3 OH

Ph

4g

OH

H N

4 OH

OH

6 OH

H N

Ph

H N

Ph

4k

OH

H N

8 OH

4l

OH

9 OH

Ph

4j

7 OH

H N

4i

OH

OH

Ph Ph

4h

5 OH

Ph

H N

OH

OH

C8H17

4m

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H. M. Corkran et al. / Bioorg. Med. Chem. xxx (2016) xxx–xxx Table 1 (continued) Entry

a

Product

Yield (%) H N

10

MIC

C8H17

61

940 lM

H N

11

C8H17

57

680 lM

Entry

H N

1

24

200 lM

2

3 N OH

NI

15

H N

28

45 lM

16

4

12

NI

10

NI

26

160 lM

18

680 lM

C16H 33

78

83–170 lM

C16H 33

90

20–40 lM

4c

61 lM

9d H N

OH OH C16H 33

44

21–41 lM

4t N

OH

18 19 20 21

NI

H N

OH

5

H N

OH OH

OH

17

45

9c

4s

OH

NI

OH OH

HO C14H 33

30

H N

OH OH

4r

OH

NI

9b OH OH

14

43

OH

4q

OH

NIb

H N

HO

OH

14

H N

OH OH

H N

R

9a

4p OH

H N

MICa

OH

NI

OH

OH

n

Yield (%)

Product OH OH

31

OH

HO

9

HO

12

14

R-NH 2

n OH

4o

OH

13

OH

NaCNBH 3

OH

4n

OH

OH

Table 2 BCG Inhibitory activity of reductive amination products O

OH

OH

b

9e C16H 33

47

22 lM

— — — —

39 lM 680 lM 140–290 lM 130 lM

OH OH

H N

4u

Ethambutol (2) Cyclododecylamine Tetradecylamine Hexadecylamine

6

9f OH OH

7

OH

9g OH OH

8

benzylamine derivatives 4i–4k (entries 5–7), which were synthesised from the parent sugars D-xylose, D-ribose, and D-arabinose, respectively, did not inhibit BCG growth, while the secondary amine 4l also had reduced inhibitory activity (entry 8). This lack of activity prompted us to increase the lipophilicity of the compounds and use the more lipophilic octylamine for the reductive amination (entries 9–11). Octylamine derivatives 4m and 4n exhibited MICs of 940 lM, while N-octylamine 4o, prepared from D-arabinose, showed the most promising activity (MIC = 680 lM). This prompted us to continue exploring the structure–activity relationships of derivatives synthesised from D-arabinose. Incorporation of the adamantyl group was initially of interest due to the promising anti-TB activity of ethylenediamine SQ109, an analogue of EMB, which is now in phase II clinical trials.3,19 Adamantyl-functionalised glycitylamine derivative 4p, however, exhibited no inhibitory activity (entry 12), while cyclododecylamine derivative 4q had a modest MIC of 200 lM (entry 13). Formation of the tertiary amine 4r, via use of di-n-butylamine, gave a glycitylamine with no inhibitory activity (entry 14), while the preparation of 4s containing the linear C14 alkyl group gave the most promising activity thus far, with an MIC = 45 lM (entry 15). This suggested that linear, rather than cyclic, alkyl groups led to improved inhibitory activity for this series of compounds. We thus prepared 4t using hexadecylamine (entry 16), and the analogous tertiary amine 4u containing an additional methyl group

H N

HO

a

Overall yield starting from D-arabinose, D-ribose or D-xylose. b MIC = minimum concentration for 100% growth inhibition in the BCG Alamar Blue Assay. c NI = No inhibition, MIC > 500 lg/mL. d Isolated as a side-product, see Ref. 10.

OH OH

H N

OH OH

9h OH OH

9

HO

H N

OH

9i OH OH

10

HO

N OH

9j OH HO

11

OH OH HO

OH OH

N

C16H 33

OH

9k a MIC = minimum concentration for 100% growth inhibition in the BCG Alamar Blue Assay. b NI = No inhibition, MIC > 500 lg/mL. c Side-product initially formed during synthesis of 13i.

on the nitrogen which was installed via the addition of formaldehyde during the reductive amination step (entry 17). Both derivatives showed good inhibitory activity (4t, MIC = 21–41 lM; 4u, MIC = 22 lM), which is comparable to that of ethambutol in our assay (entry 18, MIC = 39 lM). Moreover, both 4t and 4u can be prepared in three-steps and in good (44–47%) overall yield. While

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H. M. Corkran et al. / Bioorg. Med. Chem. xxx (2016) xxx–xxx

the inhibitory activity of these compounds is by no means the best that has been reported for a variety of potential new generation TB drugs,3 such an easy synthetic route towards active compounds is advantageous. Finally, to determine that the activity of the alkenylamines was not due to the amines alone, cyclododecylamine (entry 19), tetradecylamine (entry 20) and hexadecylamine (entry 19) were tested in the growth inhibition assay. All three showed inhibitory activity that was significantly lower than the corresponding alkenylamine. Having determined that the more lipophilic alkenylamines were able to inhibit the growth of BCG at concentrations comparable to ethambutol, we then set out to determine whether similar glycitylamines, which could be prepared in one-step via direct reductive amination of the parent sugar, would show equivalent or better inhibitory activity. To this end, D-arabinose was first subjected to a reductive amination with 1-adamantanamine to give 9a, which showed no inhibitory activity (entry 1, Table 2). Similarly, the cyclohexyl derivative 9b showed no activity (entry 2), nor did the analogous compound prepared from L-fucose 9c (entry 3), or the derivatives containing a cyclooctyl group (9d, 9e, 9f; entries 4–6). A shift to using cyclododecylamine during the reductive amination, however, led to the synthesis of derivatives 9g (entry 7) and 9h (entry 8), whereby the D-arabinose derivative 9g showed inhibitory activity (MIC = 160 lM) that was slightly better than the analogous alkenylamine. The D-arabinose derivatives containing the linear C16 alkyl groups showed better activity, that is, secondary amine 9i with an MIC of 83–170 lM (entry 9) and the methylated tertiary amine 9j with an MIC of 20–40 lM (entry 10). The activity of the latter compound is comparable to ethambutol (2) and the corresponding alkenylamine 4u, and can be synthesised in 90% yield. Here, better yields of the C16 glycitylamines could be achieved due the single step synthesis and the more ready separation of the target product from the unreacted amine starting material by silica gel flash column chromatography. Finally, the tertiary amine 9k, which was formed as a side-product during the preparation of 9i, was also tested for its inhibitory activity and determined to have a notable MIC of 61 lM. 3. Conclusion We have prepared a number of glycitylamines containing both lipophilic and hydrophilic groups. Of this family of compounds, derivatives 4t, 4u and 9j exhibit MIC activities comparable to the first line drug ethambutol (5) in our assay. While the MIC value of these new compounds is only in the micro-molar range, they are easily prepared in few steps and in good to excellent overall yield and this may be advantageous for the development of cost effective medications for the treatment of tuberculosis. Mode of action studies and in vivo analysis to ascertain the full potential of these glycitylamines as TB drugs is currently under investigation. 4. Experimental 4.1. General Unless otherwise stated, all reactions were performed under atmospheric air. H2O, MeOH (Pure Science), and EtOH (absolute, Pure Science), were distilled prior to use. EtOAc (Pure Science), and petroleum ether (Pure Science), HCl (PanReac), AcOH (Ajax Finechem), DCM (LabServ), 30% aqueous NH3 (J. T. Baker Chemical Co.), 35% aqueous NH3 (LabServ), AcCl (B&M), NaCNBH3 (Aldrich), NH4OAc (AnalaR), D-arabinose (Sigma–Aldrich), L-fucose (Sigma– Aldrich), D-xylose (Sigma–Aldrich), L-rhamnose (Sigma–Aldrich), diphenylmethylamine (Aldrich), benzylamine (Aldrich), octylamine (Aldrich), cyclohexylamine (Riedel), cyclooctylamine (Aldrich), 1-adamantylamine (Sigma), cyclododecylamine (Aldrich),

hexadexylamine (Aldrich), formaldehyde (Sigma–Aldrich), di-nbutylamine (Sigma), and tetradecylamine (Aldrich) were used as received. All chemicals obtained from commercial suppliers were used without further purification. Zn dust was activated by the careful addition of concentrated H2SO4, followed by decantation and washing with EtOH (3
) and hexanes (3
) and storage under dry hexanes. All solvents were removed by evaporation under reduced pressure. Reactions were monitored by TLC analysis on Macherey–Nagel silica gel coated plastic sheets with detection by coating with 20% H2SO4 in EtOH followed by charring at ca. 150 °C, by coating with a solution of ninhydrin in EtOH followed by charring at ca. 150 °C, or by coating with a solution of 5% KMnO4 and 1% NaIO4 in H2O followed by heating. Column chromatography was performed on Pure Science silica gel (40–63 micron). Dowex W50-X8 acidic resin (Sigma) was used for ion exchange chromatography and HP-20 (Supelco) for reverse phase chromatography. High-resolution mass spectra were recorded on a Waters Q-TOF PremierTM Tandem Mass Spectrometer using positive electro-spray ionisation. Optical rotations were recorded using an Autopol II (Rudolf Research Analytical) at 589 nm (sodium D-line). Infrared spectra were recorded as thin films using a Bruker Tensor 27 FTIR spectrometer, equipped with an Attenuated Total Reflectance (ATR) sampling accessory, and are reported in wave numbers (cm1). Nuclear magnetic resonance spectra were recorded at 20 °C in D2O, CD3OD, pyridine-d5, CDCl3, or DMSO-d6 at (80 °C) using either a Varian Unity-INOVA operating at 300 MHz or a Varian Unity operating at 500 MHz. Chemical shifts are given in ppm (d) and were internally referenced to the residual solvent peak. NMR peak assignments are based on 2D NMR experiments (COSY, HSQC, and HMBC). Pyrrolidines 5a,10 5b,15 5c14 and 5d,10 carbamates 7a,10 7b,15 7c14 and 7d,10 and glycitylamines 4a,10 4b,15 4c,14 4d,10 4e10 and 4l10 were synthesised according to previously published procedures. Methyl 5-deoxy-5-iodo-a/b-D-riboside (67% yield),10 methyl 5-deoxy-5-iodo-a/b-D-arabinoside (64% overall yield),14 and methyl 5-deoxy-5-iodo-a/b-D-xylofuranoside (61% overall yield)10 were prepared according to previously published literature procedures and used for the synthesis of the corresponding alkenylamines, as indicated below. 4.2. Synthesis 4.2.1. (2S,3S)-N-Benzhydryl-2,3-dimethoxypent-4-en-1-amine (4f) To a solution of methyl 2,3-di-O-methyl-a/b-D-xylofuranoside20 (301 mg, 1.57 mmol) in THF (20 mL) was added PPh3 (616 mg, 2.35 mmol), iodine (597 mg, 2.35 mmol), and imidazole (214 mg, 3.14 mmol) and the resulting mixture stirred at reflux for 3 h, then cooled filtered and concentrated in vacuo. The crude reaction mixture was purified by silica gel flash column chromatography (Petroleum Ether/EtOAc, 5/1, v/v) to give methyl 5-deoxy-2,3-di-O -methyl-5-iodo-a/b-D-xylofuranoside as a colourless oil (160 mg, 0.53 mmol, 34%). Rf = 0.71 (EtOAc); 1H NMR (500 MHz, CDCl3) d 4.98 (d, J1,2 = 4.4 Hz, 1H, H-1a), 4.87 (s, 1H, H-1b), 4.45 (m, 1H, H4b), 4.37 (td, J3,4 = J4,5a = 6.2, J4,5b = 7.3 Hz, 1H, H-4a), 3.86 (dd, J2,3 = 5.4, J3,4 = 6.2 Hz, 1H, H-3a), 3.77 (dd, J1,2 = 4.4, J2,3 = 5.4 Hz, 1H, H-2a), 3.74–3.73 (m, 2H, H-2b and H-3b), 3.43 (s, 3H, OMe), 3.41 (s, 3H, OMe), 3.36 (dd, J4,5a = 7.3, J5a,5b = 9.7 Hz, 1H, H-5ab), 3.31 (dd, J4,5a = 6.2, J5a,5b = 10.1 Hz, 1H, H-5aa), 3.27 (dd, J4,5b = 7.5, J5a,5b = 9.7 Hz, 1H, H-5bb), 3.16 (dd, J4,5b = 7.3, J5a,5b = 10.1 Hz, 1H, H-5ba); 13C NMR (125 MHz, CDCl3) d 108.0 (C1b), 100.8 (C1a), 88.1 (C2b), 85.9 (C2a), 83.7 (C3b), 83.5 (C3a), 81.9 (C4b), 77.8 (C4a), 60.3 (OMe), 55.5 (OMe), 3.6 (C5b), 2.4 (C5a); HRMS(ESI) m/z calcd for [C8H15O4I+Na]+: 324.9907, obsd: 324.9915. To a solution of methyl 5-deoxy-2,3-di-O -methyl-5-iodo-a/b-D-xylofuranoside (144 mg, 0.48 mmol) in EtOH/H2O (15 mL/0.3 mL) was added activated Zn (125 mg, 1.91 mmol), aminodiphenylmethane

Please cite this article in press as: Corkran, H. M.; et al. Bioorg. Med. Chem. (2016), http://dx.doi.org/10.1016/j.bmc.2015.12.036

H. M. Corkran et al. / Bioorg. Med. Chem. xxx (2016) xxx–xxx

(288 lL, 307 mg, 1.67 mmol), NaCNBH3 (102 mg, 0.96 mmol), and AcOH (50 lL) and the solution was stirred at reflux for 18 h. The reaction mixture was cooled, and dry loaded onto silica gel for purification by flash column chromatography (Petroleum ether/EtOAc, 10/1, v/v) to give alkenylamine 4f as a colourless oil (119 mg, 1 0.80 mmol, 80%). Rf = 0.53 (EtOAc); [a]17 D = 10.0 (c 1.0, CHCl3); H NMR (500 MHz, CDCl3) d 7.34–7.10 (m, 10H, aromatics), 5.68 (ddd, J3,4 = 7.7, J4,5-cis = 10.4, J4,5-trans = 17.3 Hz, 1H, H-4), 5.29 (d, J4,5-trans = 17.3 Hz, 1H, H-5trans), 5.25 (d, J4,5-cis = 10.4 Hz, 1H, H5cis), 4.78 (s, 1H, CH-Ph2), 3.77 (dd, J2,3 = 5.9, J3,4 = 7.7 Hz, 1H, H-3), 3.47 (s, 3H, OMe), 3.39 (ddd, J1a,2 = 4.1, J2,3 = 5.9, J1b,2 = 6.8 Hz, 1H, H-2), 3.30 (s, 3H, OMe), 2.74 (dd, J1a,2 = 4.1, J1a,1b = 12.3 Hz, 1H, H1a), 2.60 (dd, J1b,2 = 6.8, J1a,1b = 12.3 Hz, 1H, H-1b); 13C NMR (125 MHz, CDCl3) d 144.2, 143.8 (aromatics), 134.9 (C4), 128.5, 128.4, 127.6, 127.4, 127.3, 127.0, 126.9, (aromatics), 118.8 (C5), 83.8 (C3), 82.7 (C2), 67.7 (CH-Ph2), 58.9 (OMe), 56.7 (OMe), 47.9 (C1); HRMS(ESI) m/z calcd for [C20H25NO2+H]+: 312.1958, obsd: 312.1959. 4.2.2. (2S,3R)-1-(Benzhydrylamino)pent-4-ene-2,3-diol (4g) To a solution of methyl 5-deoxy-5-iodo-a/b-D-riboside (50 mg, 0.18 mmol) in EtOH (0.91 mL) was added activated Zn (60 mg, 0.91 mmol), aminodiphenylmethane (78 lL, 0.46 mmol) NaCNBH3 (34 mg, 0.55 mmol), and AcOH (5 drops). The mixture was stirred at reflux for 18 h then cooled and the solvent removed under reduced pressure. The resulting oil was co-evaporated three times with MeOH and HCl (1 M (aq), 2 equiv) to remove the remaining boron and was purified by silica gel flash column chromatography (DCM/EtOH/MeOH/30% NH3 (aq), 505/2/2/1 ? 305/2/2/1, v/v/v/v) to give (2S ,3R)-1-((diphenylmethyl)amino)-pent-4-ene-2,3-diol (4g) as a colourless oil (56 mg, 0.18 mmol, 96%). Rf = 0.62 (DCM/ EtOH/MeOH/30% NH3 (aq), 35/2/2/1, v/v/v/v); [a]20 D = 8.0° (c 1.0, EtOH); IR (thin film): 3345, 3064, 3033, 3009, 2983, 2960, 2926, 2855, 2830, 1646, 1587, 1499, 1455, 1429, 1322, 1288, 1257, 1187, 1144, 1090, 1026, 1001, 990, 926, 891, 840, 793, 760, 746, 696 cm1; 1H NMR (500 MHz, D2O) 7.51–7.42 (m, 10H, Ph), 5.77 (ddd, J3,4 = 6.4, J4,5-cis = 10.5, J4,5-trans = 17.1 Hz, 1H, H-4), 5.58 (s, 1H, CHPh2), 5.26 (d, J4,5-trans = 17.8 Hz, 1H, H-5-trans), 5.23 (d, J4,5-cis = 10.7 Hz, 1H, H-5-cis), 4.06 (t, J2,3 = J3,4 = 6.1 Hz, 1H, H3), 3.94 (ddd, J1b,2 = 2.5, J2,3 = 4.9, J1a,2 = 9.6 Hz, 1H, H-2), 3.23 (dd, J1b,2 = 2.2, J1a,1b = 13.2 Hz, 1H, H-1b), 3.04 (dd, J1a,2 = 10.2, J1a,1b = 13.0 Hz, 1H, H-1a); 13 C NMR (125 MHz, D2O): d 135.0 (C4), 135.0 (Ci arom.), 134.8 (Ci arom.), 129.4 (CH arom.), 129.4 (CH arom.), 129.4 (CH arom.), 129.3 (CH arom.), 127.5 (CH arom.), 127.3 (CH arom.), 118.4 (C-5), 74.1 (C-3), 69.0 (C-2), 65.7 (CHPh2), 48.2 (C-1); HRMS(ESI) m /z calcd for [C18H21O2N+H]+: 284.1651, obsd: 284.1654. 4.2.3. (2R,3R)-1-(Benzhydrylamino)pent-4-ene-2,3-diol (4h) To a solution of methyl 5-deoxy-5-iodo-a/b-D-arabinoside (52 mg, 0.19 mmol) in EtOH (0.99 mL) was added activated Zn (65 mg, 0.99 mmol), aminodiphenylmethane (85 lL, 0.50 mmol), NaCNBH3 (37 mg, 0.60 mmol), and AcOH (5 drops). The mixture was stirred at reflux for 18 h then cooled and the solvent removed under reduced pressure. The resulting oil was co-evaporated three times with MeOH and HCl (1 M (aq), 2 equiv) to remove the remaining boron and purified by silica gel flash column chromatography (DCM/EtOH/MeOH/30% NH3 (aq), 505/2/2/1 ? 305/2/2/1, v/v/v/v) to give diol 4h as a colourless oil (55 mg, 0.17 mmol, 87%). Rf = 0.66 (DCM/EtOH/MeOH/30% NH3 (aq), 35/2/2/1, v/v/v/v); [a]20 D = 1.8° (c 0.5, EtOH); IR (thin film): 3335, 3064, 3033, 3009, 2923, 2857, 2826, 1645, 1602, 1586, 1499, 1455, 1409, 1186, 1106, 1053, 1033, 1004, 991, 924, 878, 843, 792, 760, 746, 705 cm1; 1H NMR (500 MHz, D2O) 7.52–7.41 (m, 10H, Ph), 5.77 (ddd, J3,4 = 6.3, J4,5-cis = 10.6, J4,5-trans = 17.2 Hz, 1H, H-4), 5.58 (s, 1H, CHPh2), 5.28 (dt, J4,5-trans = 17.5, J5-cis,5-trans =

5

J3,5-trans = 1.3 Hz, 1H, H-5-trans), 5.23 (dt, J4,5-cis = 10.6, J5-cis,5-trans = J3,5-cis = 1.3 Hz, 1H, H-5-cis), 4.01 (ddt, J3,5-cis = J3,5-trans = 1.2 Hz, J2,3 4.9 Hz, J3,4 = 6.3 Hz, 1H, H-3), 3.93 (ddd, J1b,2 = 3.1 Hz, J2,3 = 4.9 Hz, J1a,2 = 9.8 Hz, 1H, H-2), 3.15 (dd, J1b,2 = 3.2 Hz, J1a,1b = 13.2 Hz, 1H, H-1b), 3.10 (dd, J1a,2 = 9.8 Hz, J1a,1b = 13.2 Hz, 1H, H-1a); 13 C NMR (125 MHz, D2O): d 135.2 (C-4), 135.0 (Ci arom.), 134.7 (Ci arom.), 129.4 (CH arom.), 129.4 (CH arom.), 129.3 (CH arom.), 129.3 (CH arom.), 127.5 (CH arom.), 127.3 (CH arom.), 118.3 (C-5), 73.6 (C-3), 68.9 (C-2), 65.6 (CHPh2), 48.6 (C-1); HRMS(ESI) m/z calcd for [C18H21O2N+H]+: 284.1651, obsd: 284.1650. 4.2.4. (2S,3S)-1-(Benzhydrylamino)pent-4-ene-2,3-diol (4i) To a solution of methyl 5-deoxy-5-iodo-a/b-D-xyloside (52 mg, 0.19 mmol) in EtOH (3.8 mL) was added activated Zn (62 mg, 0.95 mmol), benzylamine (41 lL, 0.38 mmol), NaCNBH3 (36 mg, 0.57 mmol), and AcOH (5 drops). The mixture was stirred at reflux for 16 h then cooled and the solvent removed under reduced pressure. The resulting oil was co-evaporated three times with MeOH and HCl (1 M (aq), 2 equiv) to remove the remaining boron. The product was purified by silica gel flash column chromatography (DCM/EtOH/MeOH/30% NH3 (aq), 405/2/2/1 ? 305/2/2/1, v/v/v/v) to give (2S,3S)-1-(benzhydrylamino)pent-4-ene-2,3-diol (4i) (43 mg, 0.18 mmol, 93%) as a colourless oil. Rf = 0.39 (DCM/EtOH/ MeOH/30% NH3 (aq), 35/2/2/1, v/v/v/v); [a]20 D = 55.2° (c 1.0, EtOH); IR (thin film): 3316, 3065, 3035, 3008, 2985, 2957, 2930, 2853, 2795, 1646, 1588, 1500, 1458, 1429, 1323, 1259, 1243, 1212, 1145, 1107, 1093, 1052, 993, 926, 852, 751, 700 cm1; 1H NMR (500 MHz, D2O) 7.49–7.47 (m, 5H, Ph), 5.83 (ddd, J3,4 = 6.3, J4,5-cis = 10.5, J4,5-trans = 17.1 Hz, 1H, H-4), 5.33 (dd, J4,5-trans = 17.1, J5-trans,5-cis = 1.0 Hz, 1H, H-5-trans), 5.28 (dd, J4,5-cis = 10.8, J5-trans,5-cis = 1.0 Hz, 1H, H-5-cis), 4.27 (s, 2H, CH2 N-Bn), 4.07 (dd, J2,3 = J3,4 = 5.4 Hz, 1H, H-3), 3.89 (ddd, J1b,2 = 2.7, J2,3 = 4.6, J1a,2 = 9.8 Hz, 1H, H-2), 3.18 (d, J1a,1b = 13.0 Hz, 1H, H-1b), 3.08 (dd, J1a,2 = 10.2, J1a,1b = 13.0 Hz, 1H, H-1a); 13 C NMR (125 MHz, D2O): d 135.3 (C-4), 130.3 (Ci arom.), 129.8 (CH arom.), 129.6 (CH arom.), 129.2 (CH arom.), 118.3 (C-5), 73.7 (C-3), 68.9 (C-2), 50.9 (CH2 Bn), 48.5 (C-1); HRMS(ESI) m/z calcd for [C12H17O2N+H]+: 208.1338, obsd: 208.1334. 4.2.5. (2S,3R)-1-(Benzylamino)pent-4-ene-2,3-diol (4j) To a solution of methyl 5-deoxy-5-iodo-a/b-D-riboside (51 mg, 0.19 mmol) in EtOH (0.93 mL) was added activated Zn (60 mg, 0.92 mmol), benzylamine (51 lL, 0.46 mmol), NaCNBH3 (35 mg, 0.56 mmol), and AcOH (5 drops). The mixture was stirred at reflux for 16 h then cooled and the solvent removed under reduced pressure. The resulting oil was co-evaporated three times with MeOH and HCl (1 M (aq), 2 equiv) to remove the remaining boron and then purified by silica gel flash column chromatography (DCM/ EtOH/MeOH/30% NH3 (aq), 105/2/2/1 ? 55/2/2/1, v/v/v/v) to give (2S,3R)-1-(benzylamino)pent-4-ene-2,3-diol (4j) as a colourless oil (37 mg, 0.15 mmol, 82%). Rf = 0.30 (DCM/EtOH/MeOH/30% NH3 (aq), 35/2/2/1, v/v/v/v); [a]20 D = 5.7° (c 1.0, EtOH); IR (thin film): 3331, 3065, 3034, 3009, 2984, 2957, 2928, 2787, 2760, 1645, 1587, 1500, 1457, 1429, 1322, 1261, 1211, 1184, 1144, 1089, 1072, 1028, 992, 927, 848, 751, 698 cm1; 1H NMR (500 MHz, D2O) 7.50–7.47 (m, 5H, Ph), 5.84 (ddd, J3,4 = 6.4, J4,5-cis = 10.5, J4,5-trans = 17.1 Hz, 1H, H-4), 5.32 (d, J4,5-trans = 18.8 Hz, 1H, H-5trans), 5.29 (d, J4,5-cis = 11.0 Hz, 1H, H-5-cis), 4.29 (d, Ja,b = 13.2 Hz, 1H, CH-a N-Bn), 4.26 (d, Ja,b = 13.2 Hz, 1H, CH-b N-Bn), 4.11 (t, J2,3 = J3,4 = 6.1 Hz, 1H, H-3), 3.89 (ddd, J1b,2 = 2.9, J2,3 = 5.4, J1a,2 = 9.8 Hz, 1H, H-2), 3.26 (dd, J1a,1b = 12.9, J1b,2 = 2.6 Hz, 1H, H1b), 3.03 (dd, J1a,2 = 10.0, J1a,1b = 13.0 Hz, 1H, H-1a); 13 C NMR (125 MHz, D2O): d 135.1 (C-4), 130.3 (Ci arom.), 129.8 (CH arom.), 129.6 (CH arom.), 129.2 (CH arom.), 118.4 (C-5), 74.1 (C-3), 68.9 (C-2), 51.0 (CH2 Bn), 48.1 (C-1); HRMS(ESI) m /z calcd for [C12H17O2N+H]+: 208.1338, obsd: 208.1335.

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H. M. Corkran et al. / Bioorg. Med. Chem. xxx (2016) xxx–xxx

4.2.6. (2R,3R)-1-(Benzylamino)pent-4-ene-2,3-diol (4k) To a solution of methyl 5-deoxy-5-iodo-a/b-D-arabinoside (49 mg, 0.18 mmol) in EtOH (0.88 mL) was added activated Zn (58 mg, 0.88 mmol), benzylamine (48 lL, 0.44 mmol), NaCNBH3 (33 mg, 0.53 mmol), and AcOH (5 drops). The mixture was stirred at reflux for 16 h then cooled and the solvent removed under reduced pressure. The resulting oil was co-evaporated three times with MeOH and HCl (1 M (aq), 2 equiv) to remove the remaining boron and purified by silica gel flash column chromatography (DCM/EtOH/MeOH/30% NH3 (aq), 305/2/2/1 ? 105/2/2/1, v/v/v/v) to give (2R,3R)-1-(benzylamino)pent-4-ene-2,3-diol (4k) as a colourless oil (34 mg, 0.14 mmol, 79%). Rf = 0.28 (DCM/EtOH/ MeOH/30% NH3 (aq), 35/2/2/1, v/v/v/v); [a]20 D = 35.7° (c 1.0, EtOH); IR (thin film): 3330, 3091, 3065, 3035, 3008, 2985, 2958, 2928, 2792, 2759, 1647, 1588, 1500, 1458, 1428, 1323, 1259, 1212, 1184, 1144, 1099, 1052, 1026, 992, 926, 854, 750, 699 cm1; 1H NMR (500 MHz, D2O) 7.49–7.46 (m, 5H, Ph), 5.83 (ddd, J3,4 = 6.5, J4,5-cis = 10.7, J4,5-trans = 17.3 Hz, 1H, H-4), 5.34 (dt, J4,5-trans = 17.3, J5-cis,5-trans = J3,5-trans = 1.2 Hz, 1H, H-5-trans), 5.28 (dt, J4,5-cis = 10.5, J5-cis,5-trans = J3,5-cis = 1.2 Hz, 1H, H-5-cis), 4.27 (s, 2H, CH2 NBn), 4.07 (ddt, J2,3 = 4.9 Hz, J3,4 = 6.4 Hz, J3,5-cis = J3,5-trans = 1.2 Hz, 1H, H-3), 3.89 (ddd, J1b,2 = 3.0, J2,3 = 4.9, J1a,2 = 10.1 Hz, 1H, H-2), 3.19 (dd, J1b,2 = 2.9, J1a,1b = 12.9 Hz, 1H, H-1b), 3.08 (dd, J1a,2 = 10.0, J1a,1b = 12.9 Hz, 1H, H-1a); 13C NMR (125 MHz, D2O): d 135.3 (C-4), 130.3 (Ci arom.), 129.8 (CH arom.), 129.7 (CH arom.), 129.2 (CH arom.), 118.3 (C-5), 73.7 (C-3), 68.9 (C-2), 51.0 (CH2 Bn), 48.6 (C-1); HRMS(ESI) m/z calcd for [C12H17O2N+H]+: 208.1338, obsd: 208.1338. 4.2.7. (2S,3S)-1-(Octylamino)pent-4-ene-2,3-diol (4m) To a solution of methyl 5-deoxy-5-iodo-a/b-D-xyloside (56 mg, 0.20430 mmol) in EtOH (4.1 mL) was added activated Zn (67 mg, 1.02 mmol), octylamine (68 lL, 0.41 mmol), NaCNBH3 (39 mg, 0.61 mmol), and AcOH (5 drops). The mixture was stirred at reflux for 17 h then cooled and the solvent removed under reduced pressure. The resulting oil was co-evaporated three times with MeOH and HCl (1 M (aq), 2 equiv) to remove the remaining boron and purified by silica gel flash column chromatography (DCM/EtOH/ MeOH/30% NH3 (aq), 305/2/2/1 ? 105/2/2/1, v/v/v/v) to give (2S, 3S)-1-(octylamino)-pent-4-ene-2,3-diol (4m) as a colourless oil (54 mg, 0.20316 mmol, 99%). Rf = 0.21 (DCM/EtOH/MeOH/30% NH3 (aq), 35/2/2/1, v/v/v/v); [a]20 D = 42.0° (c 1.0, EtOH); IR (thin film): 3321, 3089, 3015, 2957, 2924, 2855, 2800, 1647, 1593, 1455, 1407, 1378, 1315, 1285, 1250, 1152, 1140, 1103, 1091, 1051, 992, 923, 853, 755, 723, 699 cm1; 1H NMR (500 MHz, D2O) 5.86 (ddd, J3,4 = 6.6, J4,5-cis = 10.8, J4,5-trans = 17.4 Hz, 1H, H-4), 5.36 (dd, J4,5-trans = 17.3, J5-trans,5-cis = 1.5 Hz, 1H, H-5-trans), 5.30 (dd, J4,5-cis = 10.5, J5-trans,5-cis = 1.2 Hz, 1H, H-5-cis), 4.10 (t, J2,3 = J3,4 = 6.4 Hz, 1H, H-3), 3.88 (ddd, J1b,2 = 3.0, J2,3 = 4.9, J1a,2 = 10.1 Hz, 1H, H-2), 3.17 (dd, J1b,2 = 2.5, J1a,1b = 12.9 Hz, 1H, H-1b), 3.09–3.03 (m, 3H, H-1a and CH2N octyl), 1.66 (q, J = 7.3 Hz, 2H, CH2 N-octyl), 1.36–1.25 (m, 10H, 5
CH2 N-octyl), 0.83 (t, J = 7.1 Hz, 3H, CH3 N-octyl); 13 C NMR (125 MHz, D2O): d 135.3 (C-4), 118.3 (C-5), 73.7 (C-3), 69.0 (C-2), 49.1 (C-1), 47.7 (CH2 octyl), 30.9 (CH2 octyl), 28.0 (CH2 octyl), 28.0 (CH2 octyl), 25.5 (CH2 octyl), 25.1 (CH2 octyl), 21.9 (CH2 octyl), 13.3 (CH3 octyl); HRMS(ESI) m /z calcd for [C13H27O2N+H]+: 230.2120, obsd: 230.2122. 4.2.8. (2S,3R)-1-(Octylamino)pent-4-ene-2,3-diol (4n) To a solution of methyl 5-deoxy-5-iodo-a/b-D-riboside (54 mg, 0.20 mmol) in EtOH (0.99 mL) was added activated Zn (65 mg, 0.99 mmol), octylamine (82 lL, 0.49 mmol), NaCNBH3 (38 mg, 0.59 mmol), and AcOH (5 drops). The mixture was stirred at reflux for 16 h then cooled and the solvent removed under reduced pressure. The resulting oil was co-evaporated three times with MeOH

and HCl (1 M (aq), 2 equiv) to remove the remaining boron and the product purified by silica gel flash column chromatography (DCM/EtOH/MeOH/30% NH3 (aq), 305/2/2/1 ? 105/2/2/1, v/v/v/v) to give diol 4n as a colourless oil (48 mg, 0.18 mmol, 91%). Rf = 0.18 (DCM/EtOH/MeOH/30% NH3 (aq), 35/2/2/1, v/v/v/v); [a]20 D = 3.3° (c 1.0, EtOH); IR (thin film): 3342, 3120, 3049, 3024, 2957, 2924, 2855, 2806, 1646, 1590, 1445, 1401, 1314, 1230, 1148, 1098, 1027, 994, 924, 844, 760, 723, 703 cm1; 1H NMR (500 MHz, D2O) 5.90 (ddd, J3,4 = 6.4, J4,5-cis = 10.5, J4,5-trans = 17.1 Hz, 1H, H-4), 5.38 (d, J4,5-trans = 17.1 Hz, 1H, H-5-trans), 5.34 (d, J4,5-cis = 10.5 Hz, 1H, H-5-cis), 4.15 (dd, J2,3 = 5.6, J3,4 = 6.3 Hz, 1H, H-3), 3.91 (ddd, J1b,2 = 2.7, J2,3 = 5.4, J1a,2 = 9.8 Hz, 1H, H-2), 3.27 (dd, J1b,2 = 2.7, J1a,1b = 13.2 Hz, 1H, H-1b), 3.07 (t, J = 7.3 Hz, 2H, CH2N octyl), 3.03 (dd, J1a,2 = 10.0, J1a,1b = 13.0 Hz, 1H, H-1a), 1.69 (q, J = 7.1 Hz, 2H, CH2 N-octyl), 1.38–1.27 (m, 10H, 5
CH2 Noctyl), 0.86 (t, J = 7.1 Hz, 3H, CH3 N-octyl); 13 C NMR (125 MHz, D2O): d 135.3 (C-4), 118.5 (C-5), 74.1 (C-3), 69.1 (C-2), 48.8 (C-1), 47.8 (CH2 octyl), 30.9 (CH2 octyl), 28.1 (CH2 octyl), 28.1 (CH2 octyl), 25.6 (CH2 octyl), 25.2 (CH2 octyl), 21.9 (CH2 octyl), 13.4 (CH3 octyl); HRMS(ESI) m/z calcd for [C13H27O2N+H]+: 230.2120, obsd: 230.2118. 4.2.9. (2R,3R)-1-(Octylamino)pent-4-ene-2,3-diol (4o) To a solution of methyl 5-deoxy-5-iodo-a/b-D-arabinoside (51 mg, 0.19 mmol) in EtOH (3.6 mL) was added activated Zn (61 mg, 0.93 mmol), octylamine (61 lL, 0.37 mmol), NaCNBH3 (35 mg, 0.56 mmol), and AcOH (5 drops). The mixture was stirred at reflux for 18 h then cooled and the solvent removed under reduced pressure. The resulting oil was co-evaporated three times with MeOH and HCl (1 M (aq), 2 equiv) to remove the remaining boron and the product purified by silica gel flash column chromatography (DCM/EtOH/MeOH/30% NH3 (aq), 405/2/2/1 ? 305/2/2/1, v/v/v/v) to give (2R,3R)-1-(octylamino)pent-4-ene-2,3diol (4o) as a colourless oil (44 mg, 0.17 mmol, 89%). Rf = 0.19 (DCM/EtOH/MeOH/30% NH3 (aq), 35/2/2/1, v/v/v/v); [a]20 D = 41.6° (c 1.0, EtOH); IR (thin film): 3313, 3091, 3077, 3014, 2958, 2924, 2855, 2797, 1646, 1593, 1455, 1406, 1315, 1250, 1152, 1102, 1090, 1055, 991, 922, 852, 767, 723, 699 cm1; 1H NMR (500 MHz, D2O) 5.86 (ddd, J3,4 = 6.4, J4,5-cis = 10.5, J4,5-trans = 17.1 Hz, 1H, H-4), 5.36 (dt, J4,5-trans = 17.3, J5-cis,5-trans = J3,5-trans = 1.2 Hz, 1H, H-5-trans), 5.30 (dt, J4,5-cis = 10.7, J5-cis,5-trans = J3,5-cis = 1.2 Hz, 1H, H-5-cis), 4.10 (dd, J2,3 = 5.0, J3,4 = 6.4 Hz, 1H, H-3), 3.88 (ddd, J1b,2 = 3.0, J2,3 = 4.9, J1a,2 = 10.3 Hz, 1H, H-2), 3.17 (dd, J1b,2 = 2.9, J1a,1b = 13.0 Hz, 1H, H-1b), 3.06 (dd, J1a,2 = 10.2, J1a,1b = 12.9 Hz, 1H, H-1a), 3.04 (t, JCH2,CH2 = 7.3 Hz, 2H, CH2N octyl), 1.66 (q, J = 7.4 Hz, 2H, CH2 N-octyl), 1.36–1.24 (m, 10H, 5
CH2 N-octyl), 0.83 (t, J = 7.1 Hz, 3H, CH3 N-octyl); 13 C NMR (125 MHz, D2O): d 135.3 (C-4), 118.3 (C-5), 73.7 (C-3), 69.0 (C-2), 49.1 (C-1), 47.7 (CH2 octyl), 30.9 (CH2 octyl), 28.0 (CH2 octyl), 28.0 (CH2 octyl), 25.5 (CH2 octyl), 25.1 (CH2 octyl), 21.9 (CH2 octyl), 13.3 (CH3 octyl); HRMS(ESI) m/z calcd for [C13H27O2N+H]+: 230.2120, obsd: 230.2117. 4.2.10. (2R,3R)-1-(Adamantan-1-ylamino)pent-4-ene-2,3-diol (4p) To a solution of methyl 5-deoxy-5-iodo-a/b-D-arabinoside (134 mg, 0.49 mmol) in EtOH (9.8 mL) was added 1-adamantanamine (96 mg, 0.64 mmol), activated Zn (159 mg, 2.43 mmol), NaCNBH3 (93 mg, 1.48 mmol), water (0.3 mL) and AcOH (0.15 mL). The mixture was stirred under reflux overnight (18 h), then cooled, filtered and the solvent removed under reduced pressure. The product was dry loaded on silica and purified by gradient silica gel flash column chromatography (DCM/EtOH/MeOH/35% NH3 (aq), 305/2/2/1 to 5/2/2/1, v/v/v/v). Further purification by C8 reverse phase chromatography (H2O to H2O/MeOH, 1/4, v/v) followed by the addition of 1 M HCl(aq) and concentration gave

Please cite this article in press as: Corkran, H. M.; et al. Bioorg. Med. Chem. (2016), http://dx.doi.org/10.1016/j.bmc.2015.12.036

H. M. Corkran et al. / Bioorg. Med. Chem. xxx (2016) xxx–xxx

(2R,3R)-1-(adamantan-1-ylamino)pent-4-ene-2,3-diol hydrochloride (4p) as a white solid (70 mg, 0.24 mmol, 49%). Rf = 0.42 (DCM/EtOH/MeOH/30% NH3 (aq), 15/2/2/1, v/v/v/v); [a]25 D = +24.9 (c 1.0, EtOH); IR (film) 3364, 2915, 2855, 1644, 1454, 1365, 1310, 1071, 1022, 938 cm1. 1H NMR (500 MHz, D2O) d 5.90 (ddd, J3,4 = 5.9, J4,5-cis = 10.6, J4,5-trans = 17.2 Hz, 1H, H-4), 5.39 (d, J4,5-trans = 17.2 Hz, 1H, H-5-trans), 5.33 (d, J4,5-cis = 10.6 Hz, 1H, H-5-cis), 4.14 (dd, J2,3 = 5.1, J3,4 = 5.9 Hz, 1H, H-3), 3.84 (ddd, J1a,2 = 2.6, J2,3 = 5.1, J1b,2 = 10.2 Hz, 1H, H-2), 3.18 (dd, J1a,2 = 2.6, J1a,1b = 12.7 Hz, 1H, H-1a), 3.04 (dd, J1b,2 = 10.2, J1a,1b = 12.7 Hz, 1H, H-1b), 2.22–2.17 (m, 3H, H-30 ), 1.95–1.85 (m, 6H, H-20 ), 1.75 (d, J 40 a,40 b = 12.5 Hz, 3H, H-40 a), 1.66 (d, J 40 a,40 b = 12.5 Hz, 3H, H40 b); 13C NMR (125 MHz, D2O) d 135.4 (C4), 118.4 (C5), 73.9 (C3), 69.6 (C2), 57.9 (C10 ), 41.7 (C1), 37.8 (C20 ), 34.8 (C40 ), 28.8 (C30 ); HRMS(ESI) m /z calcd for [C15H25O2N+H]+: 252.1958, obsd: 252.1961. 4.2.11. (2R,3R)-1-(Cyclododecylamino)pent-4-ene-2,3-diol (4q) To a solution of methyl 5-deoxy-5-iodo-a/b-D-arabinoside (89.1 mg, 0.33 mmol) in EtOH (6.6 mL) was added cyclododecylamine (65.5 mg, 0.36 mmol), activated Zn (195 mg, 2.98 mmol), NaCNBH3 (62 mg, 0.98 mmol), water (0.2 mL), and AcOH (0.1 mL). The mixture was stirred under reflux overnight (18 h), then cooled, filtered, and the solvent removed under reduced pressure. The product was dry loaded on silica and purified by gradient silica gel flash column chromatography (DCM/EtOH/MeOH/35% NH3 (aq), 305/2/2/1 to 5/2/2/1, v/v/v/v) to yield (2R,3R)-1-(cyclododecylamino)pent-4-ene-2,3-diol hydrochloride (4q) as a white solid (38 mg, 0.12 mmol, 37%). Rf = 0.69 (DCM/EtOH/MeOH/30% NH3 (aq), 35/2/2/1, v/v/v/v); [a]21 D = 0.7 (c 1.0, EtOH); IR (film) 3335, 2932, 2863, 1642, 1471, 1446, 1096, 1025, 926, 719 cm1. 1 H NMR (500 MHz, CD3OD) d 5.98 (ddd, J3,4 = 5.6, J4,5-cis = 10.7, J4,5-trans = 17.1 Hz, 1H, H-4), 5.40 (d, J4,5-trans = 17.1 Hz, 1H, H-5-trans), 5.26 (d, J4,5-cis = 10.5 Hz, 1H, H-5-cis), 4.16–4.11 (m, 1H, H-3), 3.93–3.86 (m, 1H, H-2), 3.34–3.28 (m, 1H, H-10 ), 3.18 (d, J1a,1b = 12.7 Hz, 1H, H-1a), 3.05 (dd, J1a,2 = 9.7, J1a,1b = 12.7 Hz, 1H, H-1b), 1.80 (ddd, J = 7.3 Hz, J = 14.3 Hz, J = 22.0 Hz, 2H, H-20 a), 1.75–1.64 (m, 2H, H-20 b), 1.58–1.34 (m, 18H, H-30 –H-70 ); 13C NMR (125 MHz, CD3OD) d 138.1 (C4), 117.3 (C5), 75.1 (C3), 70.5 (C2), 57.9 (C10 ), 49.3 (C1), 27.3, 26.7, 25.7, 25.6, 25.4, 24.0, 24.0, 23.9, 23.9, 21.6, 21.3 (C20 -C60 ) HRMS(ESI) m/z calcd for [C17H33O2N+H]+: 284.2584, obsd: 284.2584. 4.2.12. (2R,3R)-1-(Dibutylamino)pent-4-ene-2,3-diol (4r) To a solution of methyl 5-deoxy-5-iodo-a/b-D-arabinoside (100.2 mg, 0.37 mmol) in EtOH (7.4 mL) was added di-n-butylamine (74 lL, 0.44 mmol), activated Zn (25 mg, 3.75 mmol), NaCNBH3 (71 mg, 1.14 mmol), water (0.22 mL), and AcOH (0.11 mL). The mixture was stirred under reflux overnight (18 h), then cooled, filtered, and the solvent removed under reduced pressure. The product was dry loaded on silica and purified by gradient silica gel flash chromatography (DCM/EtOH/MeOH/35% NH3 (aq), 305/2/2/1 to 5/2/2/1, v/v/v/v) to yield 4r as a white solid (19 mg, 0.08 mmol, 22%). Rf = 0.90 (DCM/EtOH/MeOH/30% NH3 (aq), 35/2/2/1, v/v/v/v); [a]20 D = +48.3 (c 0.82, CHCl3); IR (film) 3370, 3086, 2957, 2931, 2872, 2863, 2821, 1644, 1467, 1378, 1305, 1267, 1163, 1069, 994, 921, 735 cm1. 1H NMR (500 MHz, CDCl3) d 5.92 (ddd, J3,4 = 5.8, J4,5-cis = 10.5, J4,5-trans = 17.3 Hz, 1H, H-4), 5.38 (ddd, J3,5-trans = 1.5, J5-cis,5-trans = 1.5, J4,5-trans = 17.3 Hz, 1H, H5-trans), 5.24 (ddd, J3,5-cis = 1.4, J5-cis,5-trans = 1.5, J4,5-cis = 10.5 Hz, 1 H, H-5-cis), 3.99 (ddd, J3,5 = 1.4, J2,3 = 4.2, J3,4 = 5.8 Hz, 1H, H-3), 3.65 (ddd, J2,3 = 4.2, J1b,2 = 4.3, J1a,2 = 8.6 Hz, 1H, H-2), 2.62 (ddd, J = 8.7, J = 11.7, J 10 a,10 b = 15.9 Hz, 2H, H-10 a), 2.59 (dd, J1a,2 = 8.6, J1a,1b = 12.9 Hz, 1H, H-1a), 2.54 (dd, J1b,2 = 4.3, J1a,1b = 12.9 Hz, 1H, H-1b), 2.47 (ddd, J = 5.2, J = 8.6, J 10 a,10 b = 15.9 Hz, 2H, H-10 b), 1.53– 1.40 (m, 4H, H-20 ), 1.38–1.25 (m, 4H, H-30 ), 0.92 (t, J 30 ,40 = 7.3 Hz,

7

6H, H-40 ); 13C NMR (125 MHz, CDCl3) d 137.5 (C4), 116.5 (C5), 74.4 (C3), 69.2 (C2), 57.0 (C1), 54.2 (C10 ), 28.8 (C20 ), 20.5 (C30 ), 14.0 (C40 ); HRMS(ESI) m/z calcd for [C13H27O2N+H]+: 230.2115, obsd: 230.2122. 4.2.13. (2R,3R)-1-(Tetradecylamino)pent-4-ene-2,3-diol (4s) To a solution of methyl 5-deoxy-5-iodo-a/b-D-arabinoside (146 mg, 0.53 mmol) in EtOH (10 mL) was added tetradecylamine (136 mg, 0.64 mmol), activated Zn (291 mg, 4.45 mmol), NaCNBH3 (101 mg, 1.60 mmol), water (0.3 mL), and AcOH (0.15 mL). The mixture was stirred under reflux overnight (18 h), then cooled, filtered and the solvent removed under reduced pressure. The product was dry loaded on silica and purified by gradient silica gel flash chromatography (DCM/EtOH/MeOH/35% NH3 (aq), 305/2/2/1 to 5/2/2/1, v/v/v/v) to yield diol 4s as a white solid (74 mg, 0.24 mmol, 44%). Rf = 0.65 (DCM/EtOH/MeOH/30% NH3 (aq), 35/2/2/1, v/v/v/v); [a]21 D = +0.3 (c 0.66, EtOH); IR (film) 3380, 3275, 2954, 2916, 2847, 1646, 1468, 1420, 1326, 1252, 1162, 1119, 1095, 1053, 1030, 987, 926, 859 cm1. 1H NMR (500 MHz, CD3OD) d 5.93 (ddd, J3,4 = 6.3, J4,5-cis = 10.6, J4,5-trans = 17.2 Hz, 1H, H-4), 5.32 (ddd, J3,5-trans = 1.5, J5-cis,5-trans = 1.6, J4,5-trans = 17.2 Hz, 1H, H-5-trans), 5.19 (ddd, J3,5-cis = 1.5, J5-cis,5-trans = 1.6, J4,5-cis = 10.6 Hz, 1H, H-5-cis), 3.99 (ddd, J3,5 = 1.5, J2,3 = 5.2, J3,4 = 6.3 Hz, 1H, H3), 3.65 (ddd, J1a,2 = 3.7 Hz, J2,3 = 5.2, J1b,2 = 8.8 Hz, 1H, H-2), 2.72 (dd, J1a,2 = 3.7, J1a,1b = 12.2 Hz, 1H, H-1a), 2.63 (dt, J 10 a,20 = 7.6, J 0 10 a,10 b = 11.7 Hz, 1H, H-1 a), 2.61 (dd, J1b,2 = 8.8, J1a,1b = 12.2 Hz, 1H, H-1b), 2.58 (dt, J 10 b,20 = 7.6, J 10 a,10 b = 11.7 Hz, 1H, H-10 b), 1.56–1.49 (m, 2H, H-20 ), 1.36–1.27 (m, 22H, H-30 –H-130 ), 0.91 (t, J 13 0 0 0 = 7.0 Hz, 3H, H-14 ); C NMR (125 MHz, CD3OD) d 139.0 13 ,14 (C4), 116.7 (C5), 76.1 (C3), 73.5 (C2), 52.6 (C1), 50.6 (C10 ), 33.0, 30.7, 30.7, 30.6, 30.6. 30.6, 30.4, 29.5, 28.3, 28.2, 27.9, 23.7 (C20 -C130 ), 14.3 (C140 ); HRMS(ESI) m/z calcd for [C19H39O2N+H]+: 314.3054, obsd: 314.3058. 4.2.14. (2R,3R)-1-(Hexadecylamino)pent-4-ene,2,3-diol (4t) To a solution of methyl 5-deoxy-5-iodo-a/b-D-arabinoside (102 mg, 0.37 mmol) in EtOH (7.4 mL), was added hexadecylamine (110 mg, 0.44 mmol), activated Zn (97 mg, 1.49 mmol), NaCNBH3 (69 mg, 1.10 mmol), water (0.22 mL), and AcOH (0.11 mL). The mixture was stirred under reflux overnight (18 h), then cooled, filtered and the solvent removed under reduced pressure. The product was dry loaded on silica and purified by gradient silica gel flash chromatography (DCM/EtOH/MeOH/35% NH3 (aq), 305/2/2/1 to 5/2/2/1, v/v/v/v) to yeild (2R,3R)-1-(hexadecylamino)pent-4-ene,2,3-diol hydrochloride (4t) as as a white solid (96 mg, 0.25 mmol, 69%). Rf = 0.19 (DCM/EtOH/MeOH/30% NH3 (aq), 35/2/2/1, v/v/v/v); [a]22 D = +28.4 (c 1.0, EtOH); IR (film) 3352, 2955, 2919, 2850, 1739, 1650, 1470, 1373, 1146, 1016 cm1. 1H NMR (500 MHz, CD3OD) d 5.96 (ddd, J3,4 = 5.2, J4,5-cis = 10.7, J4,5-trans = 16.9 Hz, 1H, H-4), 5.38 (d, J4,5-trans = 16.9 Hz, 1H, H-5trans), 5.25 (dd, J5-cis,5-trans = 0.9, J4,5-cis = 10.7 Hz, 1H, H-5-cis), 4.09 (dd, J2,3 = 4.4, J3,4 = 5.2 Hz, 1H, H-3), 3.87 (dd, J1,2 = 1.7, J2,3 = 4.4 Hz, 1H, H-2), 3.12 (dd, J1a,2 = 2.5 Hz, J1a,1b = 12.6 Hz, 1H, H-1a), 3.06–2.95 (m, 3H, H-1b, H-10 ), 1.75–1.66 (m, 2H, H-20 ), 1.42–1.24 (m, 26H, H-30 –H-150 ), 0.90 (t, J 150 ,160 = 6.7 Hz, 3H, H160 ); 13C NMR (125 MHz, CD3OD) d 138.1 (C4), 117.3 (C5), 75.0 (C3), 70.5 (C2), 50.8 (C1), 48.5 (C10 ), 33.1, 30.8, 30.8, 30.8, 30.7, 30.6, 30.5, 30.2, 27.6, 27.0, 23.7 (C20 -C150 ), 14.5 (C160 ); HRMS (ESI) m/z calcd for [C21H43O2N+H]+: 342.3367, obsd: 342.3371. 4.2.15. (2R,3R)-1-(Hexadecyl(methyl)amino)pent-4-ene (4u) To a solution of hexadecylalkenylamine 4t (15.8 mg, 0.04 mmol) in MeOH (1 mL) and AcOH (0.05 mL), was added 37% aqueous formaldehyde (60 lL, 0.8 mmol), and NaCNBH3 (75.6 mg, 1.2 mmol). The solution was stirred under reflux for 24 h with additional formaldehyde (100 lL) and NaCNBH3

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H. M. Corkran et al. / Bioorg. Med. Chem. xxx (2016) xxx–xxx

(100 mg) added after 15 h and 21 h, respectively. For workup, an additional 1 mL of formaldehyde was added to remove the excess reducing agent, and the mixture was concentrated in vacuo. Purification by C8 reverse phase column chromatography, eluting in MeOH gave alkenylamine 4u as a white solid (11 mg, 0.03 mmol, 73%). Rf = 0.69 (DCM/EtOH/MeOH/30% NH3 (aq), 35/2/2/1, v/v/v/ v); [a]22 D = +28.0 (c 0.5, MeOH); IR (film) 3373, 3156, 2923, 2853, 1658, 1643, 1466, 1379, 1266, 1072, 994, 921 cm1. 1H NMR (500 MHz, CD3OD) d 5.97 (ddd, J3,4 = 5.0, J4,5-cis = 10.5, J4,5-trans = 17.5 Hz, 1H, H-4), 5.33 (d, J4,5-trans = 17.5 Hz, 1H, H-5trans), 5.20 (d, J4,5-cis = 10.5 Hz, 1H, H-5-cis), 4.04 (dd, J2,3 = 4.4, J3,4 = 5.0 Hz, 1H, H-3), 3.72 (ddd, J2,3 = 4.4, J = 7.5, J = 9.5 Hz, 1H,H2),2.53(dd, J = 4.6, J = 13.0 Hz, 1H, H-1a), 2.45–2.40 (m, 3H, H-1b, H-10 ), 2.28 (s, 3H, N-Me), 1.52–1.48 (m, 2H, H-20 ), 1.37–1.22 (m, 26H, H-30 –H-150 ), 0.90 (t, J 150 ,160 = 7.0 Hz, 3H, H-160 ); 13C NMR (125 MHz, CD3OD) d 139.1 (C4), 116.4 (C5), 76.1 (C3), 71.7 (C2), 61.1 (C1), 59.5 (C10 ), 43.0 (N-Me), 33.1, 30.8, 30.8, 30.8, 30.7, 30.7, 30.5, 28.5, 28.0, 23.7 (C20 -C150 ), 14.4 (C160 ); HRMS(ESI) m/z calcd for [C22H45O2N+H]+: 356.3523, obsd: 356.3523. 4.2.16. 5-(Adamant-1-ylamino)-5-deoxy-D-arabinitol (9a) To a solution of D-arabinose (100 mg, 0.67 mmol) in EtOH (3.4 mL), was added 1-adamantanamine (121 mg, 0.80 mmol), NaCNBH3 (126 mg, 2 mmol), water (0.34 mL), and AcOH (0.05 mL). The mixture was stirred at room temperature for 20 h. The solvent was then removed under reduced pressure, and the residue purified by Dowex-H+ cation exchange chromatography, eluting with 5–35% NH3 in EtOH/H2O. Further purification by C8 reverse phase chromatography (H2O to H2O/MeOH, 1/1, v/v) and then gradient flash chromatography (DCM/EtOH/MeOH/35% NH3 (aq), 75/2/2/1 to 35/2/2/1, v/v/v/v), followed by treatment with 1 M HCl(aq) and then concentration afforded 5-(adamant-1-ylamino)-5-deoxy-D-arabinitol hydrochloride (9a) as a white solid (30 mg, 0.09 mmol, 14%). Rf = 0.09 (DCM/EtOH/MeOH/30% NH3 (aq), 15/2/2/1, v/v/v/v); [a]25 D = +6.6 (c 0.27, EtOH); IR (film) 3365, 2916, 2854, 1645, 1455, 1365, 1310, 1071, 1020 cm1. 1H NMR (500 MHz, D2O) d 4.13 (td, J3,4 = 1.7, J4,5 = 6.4 Hz, 1H, H-4), 3.82 (dd, J1a,2 = 2.8, J1a,1b = 11.7 Hz, 1H, H-1a), 3.71 (ddd, J1a,2 = 2.8, J1b,2 = 5.9, J2,3 = 8.9 Hz, 1H, H-2), 3.65 (dd, J1b,2 = 5.9, J1a,1b = 11.7 Hz, 1H, H-1b), 3.50 (dd, J3,4 = 1.7, J2,3 = 8.9 Hz, 1H, H-3), 3.18 (d, J4,5 = 6.4 Hz, 1H, H-5), 2.19 (br s, 3H, H-30 ), 1.95–1.87 (m, 6H, H20 ), 1.74 (d, J 40 a,40 b = 12.2 Hz, 3H, H-40 a), 1.65 (d, J 40 a,40 b = 12.2 Hz, 3H, H-40 b); 13C NMR (125 MHz, D2O) d 71.1 (C3), 70.4 (C2), 66.2 (C4), 62.7 (C1), 57.8 (C10 ), 42.7 (C5), 37.8 (C20 ), 34.8 (C40 ), 28.7 (C30 ); HRMS(ESI) m/z calcd for [C15H27O4N+H]+: 286.2013, obsd: 286.2022. 4.2.17. 5-Cyclohexylamino-5-deoxy-D-arabinitol (9b) To a solution of D-arabinose (156 mg, 1.0 mmol) in EtOH (20 mL), was added cyclohexylamine (89 mg, 0.9 mmol), NaCNBH3 (194 mg, 3 mmol), water (0.5 mL), and AcOH (0.07 mL). The mixture was stirred at room temperature for 23 h. The solvent was then removed under reduced pressure and the residue purified by Dowex-H+ cation exchange chromatography, eluting with 25% aqueous NH3, to give a white solid (90 mg, 0.39 mmol, 43%) which was then treated with 1 M HCl(aq) and concentrated to afford 5cyclohexylamino-5-deoxy-D-arabinitol hydrochloride (9b) as a white solid. Rf = 0.16 (DCM/EtOH/MeOH/30% NH3 (aq), 15/2/2/1, v/v/v/v); [a]25 D = +12.8 (c 1.0, EtOH); IR (film) 3324, 2935, 2858, 1636, 1455, 1032, 896 cm1. 1H NMR (500 MHz, D2O) d 4.17 (dd, J4,5 = 3.2, J3,4 = 8.8 Hz, 1H, H-4), 3.80 (dd, J1a,2 = 2.6 Hz, J1a,1b = 11.7 Hz, 1H, H-1a), 3.70 (ddd, J1a,2 = 2.6, J1b,2 = 5.8, J2,3 = 8.7 Hz, 1H, H2), 3.63 (dd, J1b,2 = 5.8, J1a,1b = 11.7 Hz, 1H, H-1b), 3.48 (d, J3,4 = 8.8 Hz, 1H, H-3), 3.25–3.19 (m, 2H, H-5), 3.18–3.11 (m, 1H, H-10 ), 2.10–2.04 (m, 2H, H-20 a), 1.82 (d, J = 12.5 Hz, 2H, H-30 a), 1.64 (d, J = 13.2 Hz, 2H, H-40 a), 1.42–1.25 (m, 4H, H-20 b, H-30 b)

1.18–1.11 (m, 2H, H-40 b); 13C NMR (125 MHz, D2O) d 71.0 (C3), 70.4 (C2), 65.9 (C4), 62.7 (C1), 57.5 (C10 ), 47.3 (C5), 28.9, 28.5 (C20 ), 24.4 (C40 ), 23.9, 23.9 (C30 ); HRMS(ESI) m/z calcd for [C11H23O4N+H]+: 234.1700, obsd: 234.1705. 4.2.18. 1-Cyclohexylamino-1,6-dideoxy-L-galactitol (9c) To a solution of L-fucose (100 mg, 0.63 mmol) in EtOH (3 mL), was added cyclohexylamine (54 mg, 0.55 mmol), NaCNBH3 (113 mg, 1.8 mmol), water (0.3 mL), and AcOH (0.04 mL). The mixture was stirred at room temperature for 3 d. The solvent was then removed under reduced pressure, and the residue purified by Dowex-H+ cation exchange chromatography, eluting with 5–35% NH3 in H2O. Subsequent silica gradient flash chromatography (DCM/EtOH/MeOH/35% NH3 (aq), 105/2/2/1 to 15/2/2/1, v/v/v/v) afforded 1-cyclohexylamino-1,6-dideoxy-D-galactitol (9c) (41 mg, 0.17 mmol, 30%) as a white solid. Rf = 0.40 (DCM/EtOH/MeOH/30% NH3 (aq), 15/2/2/1, v/v/v/v); [a]25 D = +10.6 (c 0.86, EtOH); IR (film) 3351, 2948, 2836, 1651, 1450, 1410, 1114, 1017 cm1. 1H NMR (500 MHz, D2O) d 4.14 (ddd, J2,3 = 1.6, J1b,2 = 4.5, J1a,2 = 8.5 Hz, 1H, H-2), 4.10 (qd, J4,5 = 1.7, J5,6 = 6.7 Hz, 1H, H-5), 3.58 (dd, J2,3 = 1.6, J3,4 = 9.3 Hz, 1H, H-3), 3.47 (dd, J4,5 = 1.7, J3,4 = 9.3 Hz, 1H, H-4), 3.11 (dd, J1a,2 = 8.5, J1a,1b = 13.0 Hz, 1H, H-1a), 3.09 (dd, J1b,2 = 4.5, J1a,1b = 13.0 Hz, 1H, H-1b), 3.00–2.94 (m, 1H, H-10 ), 2.07–2.01 (m, 2H, H-20 a), 1.84–1.77 (m, 2H, H-30 a), 1.69–1.64 (m, 1H, H-40 a), 1.34–1.28 (m, 4H, H-20 b, H-30 b), 1.25 (d, J5,6 = 6.7 Hz, 3H, H-6), 1.23–1.12 (m, 1H, H-40 b); 13C NMR (125 MHz, D2O) d 72.7 (C4), 70.9 (C3), 67.1 (C2), 65.8 (C5), 57.0 (C10 ), 47.7 (C1), 29.9, 29.6 (C20 ), 24.8 (C40 ), 24.1, 24.1 (C30 ), 18.6 (C6); HRMS(ESI) m/z calcd for [C12H25O4N+H]+: 248.1856, obsd: 248.1866. 4.2.19. 5-Cyclooctylamino-5-deoxy-D-arabinitol (9d) To a solution of D-arabinose (100 mg, 0.67 mmol) in EtOH (13.3 mL), was added cyclooctylamine (77 mg, 0.60 mmol), NaCNBH3 (126 mg, 2 mmol), and water (0.4 mL). The mixture was stirred at room temperature for 4 h. The solvent was then removed under reduced pressure, and the residue purified by Dowex-H+ cation exchange chromatography eluting with 5–35% NH3 in EtOH/H2O to give 5-cyclooctylamino-5-deoxy-D-arabinitol (9d) as a white solid (70 mg, 0.27 mmol, 45%). Rf = 0.18 (DCM/ EtOH/MeOH/30% NH3 (aq), 15/2/2/1, v/v/v/v); [a]25 D = +4.9 (c 1.0, EtOH); IR (film) 3348, 2925, 2857, 1642, 1469, 1446, 1054, 879 cm1. 1H NMR (500 MHz, CD3OD) d 3.97 (td, J3,4 = 2.1, J4,5 = 6.2 Hz, 1H, H-4), 3.79 (dd, J1a,2 = 3.2, J1a,1b = 10.9 Hz, 1H, H1a), 3.66 (ddd, J1a,2 = 3.2, J1b,2 = 5.8, J2,3 = 8.0 Hz, 1H, H-2), 3.62 (dd, J1b,2 = 5.8, J1a,1b = 10.9 Hz, 1H, H-1b), 3.42 (dd, J3,4 = 2.1, J2,3 = 8.0 Hz, 1H, H-3), 2.83 (d, J4,5 = 6.2 Hz, 2H, H-5), 2.83–2.79 (m, 1H, H-10 ), 1.87–1.73 (m, 4H, H-20 -50 ), 1.61–1.59 (m, 4H, H-20 50 ), 1.59–1.46 (m, 6H, H-20 -50 ); 13C NMR (125 MHz, CD3OD) d 74.3 (C3), 73.0 (C2), 69.7 (C4), 64.9 (C1), 59.2 (C10 ), 51.0 (C5), 33.0, 28.1, 26.9, 25.3 (C20 -50 ); HRMS(ESI) m/z calcd for + [C13H27O4N+H] : 262.2013, obsd: 262.2016. 4.2.20. 1-Cyclooctylamino-1,6-dideoxy-L-galactitol (9e) To a solution of L-fucose (100 mg, 0.63 mmol) in EtOH (3 mL), was added cyclooctylamine (84 mg, 0.66 mmol), NaCNBH3 (113 mg, 1.8 mmol), water (0.3 mL), and AcOH (0.04 mL). The mixture was stirred at room temperature for 22 h. The solvent was then removed under reduced pressure, and the residue purified by Dowex-H+ cation exchange chromatography, eluting with 5– 35% NH3 in H2O. Gradient flash chromatography (DCM/EtOH/ MeOH/35% NH3 (aq), 105/2/2/1 to 55/2/2/1, v/v/v/v), followed by treatment with 1 M HCl and concentration afforded 1-cyclooctylamino-1,6-dideoxy-D-galactitol hydrochloride (9e) as a white solid (19 mg, 0.07 mmol, 12%). Rf = 0.16 (DCM/EtOH/MeOH/30% NH3 (aq), 15/2/2/1, v/v/v/v); [a]25 D = +10.5 (c 1.0, EtOH); IR (film) 3355, 2928, 2858, 1642, 1450, 1285, 1052, 1023 cm1. 1H NMR

Please cite this article in press as: Corkran, H. M.; et al. Bioorg. Med. Chem. (2016), http://dx.doi.org/10.1016/j.bmc.2015.12.036

H. M. Corkran et al. / Bioorg. Med. Chem. xxx (2016) xxx–xxx

(500 MHz, D2O) d 4.13 (ddd, J2,3 = 1.6, J1b,2 = 4.4, J1a,2 = 9.1 Hz, 1H, H-2), 4.01 (qd, J4,5 = 1.7, J5,6 = 6.6 Hz, 1H, H-5), 3.51 (dd, J2,3 = 1.6, J3,4 = 9.4 Hz, 1H, H-3), 3.39 (dd, J4,5 = 1.7, J3,4 = 9.4 Hz, 1H, H-4), 3.35 (tt, J 10 ,20 a = 3.5, J 10 ,20 b = 9.3 Hz, 1H, H-10 ), 3.18 (dd, J1a,2 = 9.1, J1a,1b = 13.2 Hz, 1H, H-1a), 3.14 (dd, J1b,2 = 4.4, J1a,1b = 13.2 Hz, 1H, H-1b), 1.92–1.85 (m, 2H, H-20 a), 1.73–1.65 (m, 4H, H-20 b, H30 a), 1.60–1.40 (m, 7H, H-30 b-50 a), 1.37–1.30 (m, 1H, H-50 b), 1.17 (d, J5,6 = 6.6 Hz, 3H, H-6); 13C NMR (125 MHz, D2O) d 72.6 (C4), 70.7 (C3), 66.2 (C2), 65.6 (C5), 59.0 (C10 ), 47.8 (C1), 29.2, 28.7 (C20 ), 25.6, 25.6 (C40 ), 25.2 (C50 ), 23.3 (C30 ), 18.6 (C6); HRMS(ESI) m/z calcd for [C14H29O4N+H]+: 276.2169, obsd: 276.2170. 4.2.21. 1-Cyclooctylamino-1,6-dideoxy-L-mannitol (9f) To a solution of L-rhamnose (100 mg, 0.63 mmol) in EtOH (5.5 mL), was added cyclooctylamine (62 mg, 0.49 mmol), NaCNBH3 (104 mg, 1.7 mmol), water (0.3 mL), and AcOH (0.15 mL). The mixture was stirred at room temperature for 19 h. The solvent was then removed under reduced pressure, and the residue purified by Dowex-H+ cation exchange chromatography, eluting with 5–35% NH3 in EtOH/H2O. Silica gradient flash chromatography (DCM/EtOH/MeOH/35% NH3 (aq), 105/2/2/1 to 5/2/2/1, v/v/v/v), followed by treatment with 1 M HCl(aq) and concentration afforded 1-cyclooctylamino-1,6-dideoxy-L-mannitol hydrochloride (9f) as a white solid (16 mg, 0.05 mmol, 10%). Rf = 0.36 (DCM/EtOH/MeOH/30% NH3 (aq), 5/2/2/1, v/v/v/v); [a]25 (c 0.38, EtOH); IR (film) 2930, 2851, 1641, 1450, D = +1.3 1306, 1071, 1019 cm1. 1H NMR (500 MHz, D2O) d 3.94 (ddd, J1a,2 = 3.0, J2,3 = 8.2, J1b,2 = 9.5 Hz, 1H, H-2), 3.82 (dq, J5,6 = 6.3, J4,5 = 8.1 Hz, 1H, H-5), 3.78 (dd, J3,4 = 1.5, J2,3 = 8.2 Hz, 1H, H-3), 3.51 (dd, J3,4 = 1.5, J4,5 = 8.1 Hz, 1H, H-4), 3.46–3.40 (m, 1H, H-10 ), 3.41 (dd, J1a,2 = 3.0, J1a,1b = 13.0 Hz, 1H, H-1a), 3.11 (dd, J1b,2 = 9.5, J1a,1b = 13.0 Hz, 1H, H-1b), 1.98–1.90 (m, 2H, H-20 a), 1.81–1.70 (m, 4H, H-20 b, H-30 a), 1.67–1.45 (m, 7H, H-30 b-50 a), 1.42–1.35 (m, 1H, H-50 b), 1.25 (d, J5,6 = 6.3 Hz, 3H, H-6); 13C NMR (125 MHz, D2O) d 72.9 (C4), 70.9 (C3), 66.9 (C2), 66.8 (C5), 59.0 (C10 ), 47.5 (C1), 29.3, 28.6 (C20 ), 25.6, 25.6 (C40 ), 25.1 (C50 ), 23.3, 23.3 (C30 ), 18.9 (C6); HRMS(ESI) m/z calcd for [C14H29O4N+H]+: 276.2169, obsd: 276.2175. 4.2.22. 5-Cyclododecylamino-5-deoxy-D-arabinitol (9g) To a solution of D-arabinose (100 mg, 0.67 mmol) in EtOH (13.3 mL), was added cyclododecylamine (243 mg, 1.33 mmol), NaCNBH3 (126 mg, 2 mmol), and water (0.4 mL). The mixture was stirred at room temperature for 5 h then the solvent removed under reduced pressure. The product was purified first by gradient flash chromatography (DCM/EtOH/MeOH/35% NH3 (aq), 305/2/2/1 to 5/2/2/1, v/v/v/v), followed Dowex-H+ cation exchange (5–35% NH3 in EtOH/H2O) to give a white solid, 9g, which was treated with 1 M HCl(aq) and concentrated to give the HCl salt (61 mg, 0.17 mmol, 26%). Rf = 0.24 (DCM/EtOH/MeOH/30% NH3 (aq), 15/2/2/1, v/v/v/v); [a]25 (c 0.93, EtOH); IR (film) 3330, D = +8.1 2929, 2862, 1576, 1471, 1446, 1074 cm1. 1H NMR (500 MHz, CD3OD) d 4.20–4.17 (m, 1H, H-4), 3.80 (dd, J1a,2 = 2.8, J1a,1b = 10.5 Hz, 1H, H-1a), 3.68 (ddd, J1a,2 = 2.8, J1b,2 = 5.4, J2,3 = 8.1 Hz, 1H, H-2), 3.65 (dd, J1b,2 = 5.4, J1a,1b = 10.5 Hz, 1H, H-1b), 3.47 (dd, J3,4 = 1.7, J2,3 = 8.1 Hz, 1H, H-3), 3.31 (dt, J 10 ,20 a = 1.6, J 10 ,20 b = 3.2 Hz, 1H, H-10 ), 3.21 (dd, J4,5a = 8.4, J5a,5b = 12.8 Hz, 1H, H-5a), 3.18 (dd, J4,5b = 4.4, J5a,5b = 12.8 Hz, 1H, H-5b), 1.91–1.78 (m, 2H, H-20 a), 1.74–1.66 (m, 2H, H-20 b), 1.57–1.35 (m, 18H, H-30 -H-70 ); 13C NMR (125 MHz, CD3OD) d 73.3 (C3), 72.7 (C2), 67.4 (C4), 64.6 (C1), 57.9 (C10 ), 49.7 (C5), 27.3, 26.7 (C20 ), 25.7, 25.6, 25.4, 24.1, 24.0, 23.9, 21.6, 21.3 (C30 -C70 ); HRMS(ESI) m/z calcd for [C17H35O4N+H]+: 318.2639, obsd: 318.2648.

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4.2.23. 1-Cyclododecylamino-1,6-dideoxy-L-galactitol (9h) To a solution of L-fucose (165 mg, 1.0 mmol) in EtOH (20 mL), was added cyclododecylamine (294 mg, 1.5 mmol), NaCNBH3 (189 mg, 3.0 mmol), water (0.5 mL), and AcOH (0.07 mL). The mixture was stirred at room temperature for 7 d. The solvent was then removed under reduced pressure, and the residue purified by Dowex-H+ cation exchange chromatography eluting with 5–35% NH3 in EtOH/H2O. Reverse phase chromatography (HP20 beads, 10–100% MeOH), afforded a white solid (59.8 mg, 0.18 mmol, 18%) that was subsequently treated with 1 M HCl(aq) and concentrated to provide 1-cyclododecylamino-1,6-dideoxy-D-galactitol hydrochloride (9h). Rf = 0.29 (DCM/EtOH/MeOH/30% NH3 (aq), 5/2/2/1, v/v/v/v); [a]25 D = +6.0 (c 0.29, EtOH); IR (film) 3366, 2928, 2859, 1637, 1471, 1448, 1414, 1052, 996 cm1. 1H NMR (500 MHz, D2O) d 4.21 (t, J1,2 = 6.3 Hz, 1H, H-2), 4.07 (q, J5,6 = 6.6 Hz, 1H, H-5), 3.56 (d, J3,4 = 9.5 Hz, 1H, H-3), 3.44 (d, J3,4 = 9.5 Hz, 1H, H-4), 3.32–3.38 (m, 1H, H-10 ), 3.24 (d, J1,2 = 6.3 Hz, 2H, H-1), 1.74–1.84 (m, 2H, H-20 a), 1.63–1.73 (m, 2H, H-20 b), 1.32–1.51 (m, 18H, H-30 -H-70 ), 1.22 (d, J5,6 = 6.6 Hz, 3H, H6); 13C NMR (125 MHz, D2O) d 72.5 (C4), 70.7 (C3), 66.0 (C2), 65.6 (C5), 56.9 (C10 ), 48.0 (C1), 25.7, 25.3, 24.0, 24.0, 23.9, 22.5, 22.3, 22.3, 22.2, 19.9, 19.7(C20 -C70 ), 18.5 (C6); HRMS(ESI) m/z calcd for [C18H37O4N+H]+: 332.2795, obsd: 332.2802. 4.2.24. 5-Deoxy-5-hexadecylamino-D-arabinitol (9i) To a solution of D-arabinose (100 mg, 0.67 mmol) in EtOH (46.6 mL), was added hexadecylamine (1.66 g, 6.9 mmol), NaCNBH3 (62.1 mg, 1.0 mmol), and AcOH (2.6 mL). The mixture was stirred at 50 °C for 4 h then the solvent was removed under reduced pressure. The residue was co-evaporated with 2
25 mL of 5% HCl in methanol (w/v), then purified by gradient silica gel flash chromatography (DCM/EtOH/MeOH/35% NH3 (aq), 105/2/2/1 to 15/2/2/1, v/v/v/v) to give HCl salt 9i as a white solid (195 mg, 0.52 mmol, 78%). Rf = 0.40 (DCM/EtOH/MeOH/35% NH3 (aq), 5/2/2/1, v/v/v/v); IR (film) 3268, 2917, 2849, 1467,1093, 1040, 878 cm1. 1H NMR (300 MHz, DMSO-d6, 80 °C) d 3.78–3.71 (m, 1H, H-4), 3.60 (dd, J1a,2 = 3.7, J1a,1b = 10.4 Hz, 1H, H-1a), 3.50 (ddd, J1a,2 = 3.7, J1b,2 = 5.7, J2,3 = 7.5 Hz, 1H, H-2), 3.42 (dd, J1b,2 = 5.7, J1a,1b = 10.4 Hz, 1H, H-1b), 3.31 (dd, J3,4 = 2.5, J2,3 = 7.5 Hz, 1H, H-3), 2.71–2.62 (m, 2H, H-5), 2.59–2.52 (m, 2H, H-10 ), 1.47–1.36 (m, 2H, H-20 ), 1.36–1.21 (m, 26H, H-30 -H-150 ), 0.87 (t, J150 ,160 = 6.8 Hz, 3H, H-160 ); 13C NMR (75 MHz, DMSO-d6, 80 °C) d 72.9 (C3), 71.7 (C2), 68.5 (C4), 63.5 (C1), 52.4 (C5), 48.9 (C5), 30.9, 28.6 (br. s), 26.4, 21.6 (C20 -C150 ), 13.5 (C160 ); HRMS (ESI) m/z calcd for [C21H45O4N+H]+: 376.3421, obsd: 376.3421. 4.2.25. 5-Deoxy-5-hexadecylmethylamino-D-arabinitol (9j) To a solution of D-arabinose (101.5 mg, 0.67 mmol) in MeOH (46.6 mL), was added hexadecylamine (1.65 g, 6.8 mmol), NaCNBH3 (64.8 mg, 1 mmol), and AcOH (2.6 mL). The mixture was stirred at 45 °C for 4 h before 1 mL of 37% aqueous formaldehyde (13.3 mmol) was added. After a further 3 h, additional NaCNBH3 (840 mg, 13.3 mmol) was added and the reaction was left to stir overnight (16 h), then the solvent was removed under reduced pressure. The residue was co-evaporated with 2
25 mL of 5% HCl in methanol (w/v), then the residue was purified by gradient silica gel flash chromatography (DCM/EtOH/MeOH/35% NH3 (aq), 105/2/2/1 to 85/2/2/1, v/v/v/v) affording 9j as a white solid that was converted into the HCl salt by the addition of HCl (1.2 M, aq) and concentration (236 mg, 0.61 mmol, 90%). Rf = 0.57 (DCM/EtOH/MeOH/35% NH3 (aq), 5/2/2/1, v/v/v/v); [a]28 D = +8.0 (c 1.0, MeOH); IR (film) 3333, 2953, 2918, 2850, 1467, 1081, 1033, 736 cm1. 1H NMR (300 MHz, CD3OD) d 4.29 (d, J = 9.3 Hz, 1H, H4), 3.80 (app. d, J = 8.0 Hz, 1H, H-1a), 3.72–3.60 (m, 2H, H-1b and

Please cite this article in press as: Corkran, H. M.; et al. Bioorg. Med. Chem. (2016), http://dx.doi.org/10.1016/j.bmc.2015.12.036

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H-2), 3.48–3.34 (m, 2H, H-3 and H-5a), 3.26–3.10 (m, 3H, H-10 and H-5b), 2.93 (s, 3H, N-Me), 1.84–1.69 (m, 2H, H-20 ), 1.46–1.24 (m, 26H, H-30 -H-150 ), 0.90 (t, J 150 ,160 = 6.6 Hz, 3H, H-160 ); 13C NMR (125 MHz, CD3OD) d 71.4 (C3), 71.2 (C2), 64.7 (C4), 63.3 (C1), 55.5 (C5), 56.6 (C10 ), 40.2 (N-Me), 31.7, 29.4, 29.4, 29.3, 29.2, 29.1, 28.9, 26.3, 22.3 (C30 -C150 ), 23.8 (C20 ), 13.1 (C160 ); HRMS (ESI) m/z calcd for [C22H47O4N+H]+: 390.3578, obsd: 390.3594. 4.2.26. 5-Deoxy-5-hexadecylamino-bis-D-arabinitol (9k) 5-deoxy-5-hexadecylamino-bis-D-arabinitol (9k) was isolated as a side-product during a strategy used to initially prepare 9i. The protocol used was as follows: To a solution of D-arabinose (197 mg, 1.3 mmol) in EtOH (16.8 mL), was added hexadecylamine (576 mg, 2.4 mmol), NaCNBH3 (124 mg, 2.0 mmol), and AcOH (0.96 mL). The mixture was stirred at 50 °C for 18 h then the solvent was removed under reduced pressure. The residue was co-evaporated with 2
25 mL of 5% HCl in methanol (w/v), then purified by gradient flash silica chromatography (DCM/EtOH/ MeOH/35% NH3 (aq), 105/2/2/1 to 15/2/2/1, v/v/v/v) to give 9i as a white solid (168.6 mg, 0.45 mmol, 34%) and 5-deoxy-5-hexadecylamino-bis-D-arabinitol (9k) also a white solid, as a by-product (14 mg, 0.03 mmol, 4%). Rf = 0.17 (DCM/EtOH/MeOH/35% NH3 (aq), 5/2/2/1, v/v/v/v); [a]26 (c 1.0, pyridine); IR (film) D = +9.0 3357, 2954, 2922, 2853, 1466, 1203, 1135, 1080 cm1. 1H NMR (500 MHz, Pyridine-d5) d 4.98–4.89 (m, 1H, H-4), 4.59–4.54 (m, 1H, H-2), 4.52 (dd, J1a,2 = 3.8, J1a,1b = 10.7 Hz, 1H, H-1a), 4.39 (dd, J1b,2 = 5.6, J1a,1b = 10.7 Hz, 1H, H-1b), 4.32 (d, J2,3 = 8.0 Hz, 1H, H-3), 3.27 (dd, J4,5a = 7.9, J5a,5b = 12.9 Hz, 1H, H-5a), 3.12 (dd, J4,5b = 5.4, J5a,5b = 12.9 Hz, 1H, H-5b), 2.78–2.65 (m, 2H, H-10 ), 1.63–1.54 (m, 2H, H-20 ), 1.32–1.15 (m, 26H, H-30 -H-150 ), 0.88 (t, J 13 0 C NMR (125 MHz, Pyridine-d5) d 73.9 150 ,160 = 6.9 Hz, 3H, H-16 ); (C3), 73.5 (C2), 68.2 (C4), 65.5 (C1), 59.4 (C5), 56.5 (C10 ), 32.5, 30.4, 30.3, 30.1, 30.0, 27.9, 23.3 (C30 -C150 ), 26.6 (C20 ), 14.6 (C160 ); HRMS(ESI) m/z calcd for [C26H55O8N+H]+: 510.4000, obsd: 510.4004. 4.3. Biology 4.3.1. BCG Alamar Blue growth inhibition assay protocol 4.3.1.1. Bacteria. Stock solutions of BCG (1.5
107 bacteria per mL) were stored at 80 °C. These were defrosted with repeated cycles of 10 s sonication, followed by 10 s on ice. A stock sample of BCG was diluted to a concentration of 8
104 bugs per mL using sterile Tween albumin broth [Dubos broth base/OADC] to suspend. 4.3.1.2. Compounds. Compounds were dissolved in one of two ways, depending on solubility: (a) for compounds soluble in phosphate buffered saline (PBS) with up to 5% DMSO, a solution was prepared with sterile PBS and sterile DMSO at double the desired concentration and these were filter sterilised using Acrodisc 13 mm syringe filters, with 0.22 lm pore size into sterile eppendorf tubes. A 200 lL aliquot of this solution was then added to the wells for serial dilution. (b) Compounds soluble only in DMSO were prepared at forty times the desired starting concentration, in sterile eppendorf tubes. A 10 lL aliquot of this solution and 190 lL of PBS was then added to the wells for serial dilution. 4.3.1.3. Minimum inhibitory concentration. Optical bottom black 96 well plates were used for the screening of the compounds. The compounds were tested in triplicate and tested over three serial dilutions, starting at a concentration of 500 mg/mL, with repeated serial dilutions at a lower concentrations being performed on compounds showing initial inhibitory activity. Ethambutol was used as a positive control. To determine if the compounds

had any inherent redox potential which might affect readouts, 200 lL solutions of compounds and PBS were added to individual control wells. Control wells of bacteria only, and PBS medium only were also prepared. 100 lL of BCG solution was added to all wells except the PBS only and compound only wells, and the plate was incubated at 37 °C and 5% CO2 for 7 days. Alamar Blue dye (20 lL) was then added to all test wells on day 7, and the plate was incubated for another 24 h before fluorescence was measured (excitation at 544 nm, emission at 590 nm) using a FLUOstar OPTIMA plate reader. The results were graphed to determine the MICs. The lowest drug concentration effecting 100% growth inhibition was considered the MIC. Acknowledgments This work was supported by the Lottery Health Board of New Zealand, the Wellington Medical Research Foundation and the Marsden Fund Council. Supplementary data Supplementary data (copies of 1H NMR and 13C NMR spectra of all new compounds) associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.bmc.2015.12.036. References and notes 1. WHO. Global tuberculosis report 2014. Geneva: World Health Organization, 2014. http://www.who.int/tb/publications/global_report/en/ (accessed Oct 20, 2015). 2. (a) Mueller, P.; Pieters, J. Immunobiology 2006, 211, 549; (b) Russell, D. G.; Cardona, P.-J.; Kim, M.-J.; Allain, S.; Altare, F. Nat. Immunol. 2009, 10, 943. 3. Zumla, A.; Nahid, P.; Cole, S. T. Nat. Rev. Drug. Disc. 2013, 12, 388. 4. Mulchin, B. J.; Newton, C. G.; Baty, J. W.; Grasso, C. H.; Martin, W. J.; Walton, M. C.; Dangerfield, E. M.; Plunkett, C. H.; Berridge, M. V.; Harper, J. L.; Timmer, M. S. M.; Stocker, B. L. Bioorg. Med. Chem. 2010, 18, 3238. 5. Zumla, A.; Nahid, P.; Cole, S. T. Nat. Rev. Drug Disc. 2013, 12, 388. 6. Wolucka, B. A.; de McNeil, M. R.; Hoffman, E.; Chojnacki, T.; Brennan, P. J. J. Biol. Chem. 1994, 269, 23328. 7. (a) Lowary, T. L. Mycobacterial Cell Wall Components. In Glycoscience: Chemistry and Chemical Biology; Fraser-Reid, B., Tatsuta, K., Theim, J., Eds.; Springer-Verlag: Berlin, Germany, 2001; pp 2005–2080; (b) Brennan, P. J.; Nikaido, H. Annu. Rev. Biochem. 1995, 64, 29. 8. For some reviews on the potential of pyrrolidines as glycosidase and/or glycosyl transferase inhibitors, see: (a) Asano, N.; Kato, A.; Watson, A. A. MiniRev. Med. Chem. 2001, 1, 145; (b) Asano, N.; Nash, R. J.; Molyneux, R. J.; Fleet, G. W. J. Tetrahedron: Asymmetry 2000, 11, 1645; (c) Winchester, B.; Fleet, G. W. Glycobiology 1992, 2, 199; Wang, S.; Vidal, S. In In Carbohydrate Chemistry; The Royal Society of Chemistry, 2013; Vol. 39, pp 78–101. 9. Dangerfield, E. M.; Plunkett, C. H.; Win-Mason, A. L.; Stocker, B. L.; Timmer, M. S. M. J. Org. Chem. 2010, 75, 5470. 10. Dangerfield, E. M.; Timmer, M. S. M.; Stocker, B. L. Org. Lett. 2009, 11, 535. 11. Win-Mason, A. L.; Dangerfield, E. M.; Tyler, P. C.; Stocker, B. L.; Timmer, M. S. M. Eur. J. Org. Chem. 2011, 4008. 12. Stocker, B. L.; Jongkees, S. A. K.; Win-Mason, A. L.; Dangerfield, E. M.; Withers, S. G.; Timmer, M. S. M. Carbohydr. Res. 2013, 367, 29. 13. Win-Mason, A. L.; Jongkees, S. A. K.; Withers, S. G.; Tyler, P. C.; Timmer, M. S. M.; Stocker, B. L. J. Org. Chem. 2011, 76, 9611. 14. Dangerfield, E. M.; Gulab, S. A.; Plunkett, C. H.; Timmer, M. S. M.; Stocker, B. L. Carbohydr. Res. 2010, 345, 1360. 15. Dangerfield, E. M.; Plunkett, C. H.; Stocker, B. L.; Timmer, M. S. M. Molecules 2009, 14, 5298. 16. Yajko, D. M.; Madej, J. J.; Lancaster, M. V.; Sanders, C. A.; Cawthon, V. L.; Gee, B.; Babst, A.; Hadley, W. K. J. Clin. Microbiol. 1995, 33, 2324. 17. Collins, L. A.; Franzblau, S. G. Antimicrob. Agents Chemother. 1997, 41, 1004. 18. For some examples of TB inhibitors based on AraT inhibitors, see: (a) Centrone, C. A.; Lowary, T. L. J. Org. Chem. 2002, 67, 8862; (b) Naresh, K.; Bharati, B. K.; Avaji, P. G.; Jayaraman, N.; Chatterji, D. Org. Biomol. Chem. 2010, 8, 592; (c) Bosco, M.; Bisseret, P.; Constant, P.; Eustache, J. Tetrahedron Lett. 2007, 48, 153; (d) Maddry, J. A.; Bansal, N.; Bermudez, L. E.; Comber, R. N.; Orme, I. M.; Suling, W. J.; Wilson, L. N.; Reynolds, R. C. Bioorg. Med. Chem. Lett. 1998, 8, 237. 19. Protopopova, M.; Hanrahan, C.; Nikonenko, B.; Samala, R.; Chen, P.; Gearhart, J.; Einck, L.; Nacy, C. A. J. Antimicrob. Chemother. 2005, 56, 968. 20. Kovácˇ, P.; Petríková, M. Carbohydr. Res. 1971, 19, 249.

Please cite this article in press as: Corkran, H. M.; et al. Bioorg. Med. Chem. (2016), http://dx.doi.org/10.1016/j.bmc.2015.12.036