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S-1
Synthesis of 2-deoxy-2,2-difluoro-α-maltosyl fluoride and its X-ray structure in complex with Streptomyces coelicolor GlgEI-
V279S Sandeep Thanna‡, Jared J. Lindenberger‡, Vishwanath V. Gaitonde, Donald R. Ronning* and
Steven J. Sucheck*
Department of Chemistry, The University of Toledo, 2801 W. Bancroft Street, MS602, Toledo, OH, USA 43606
Supplementary Information Page S-1: Contents
Page S-5: Enzyme substrate assay for α-MTF
Page S-6: Fig. S-1. Evaluation of α-MTF as a substrate for Sco GlgEI-V279S.
Page S-7: Synthesis of per-O-acetyl-2-fluoro-maltal (1) and 3,6-di-O-acetyl-4-O-(2’,3’,4’,6’-tetra-O-acetyl-α-D-glucopyranosyl)-2-deoxy-2-fluoro-α-D-mannosyl bromide (14).
Page S-8: Scheme S-1. Synthesis of per-O-acetyl-2-fluoro-maltal (1) and 3,6-di-O-acetyl-4-O-(2’,3’,4’,6’-tetra-O-acetyl-α-D-glucopyranosyl)-2-deoxy-2-fluoro-α-D-mannosyl bromide (14). Page S-9 to S-15: Experimentals for scheme S-1
2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-1,2,3,6-tetra-O-acetyl-α-D-glucopyranose (8)2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-2,3,6-tri-O-acetyl-α-D-glucopyranosyl bromide (9)2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-α-D-glycal (10)2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α/β-D-gluco-and D-mannopyranoses (11)2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-1,3,6-tri-O-acetyl-2-deoxy-2-fluoro-α/β-D-gluco-and D-mannopyranoses (12)2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-gluco-and D-mannopyranosyl fluoride (13)2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-glycal (1)2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-mannopyranosyl bromide (14)
Page S-16: Synthesis 5-fluoro-β-D-idosyl fluoride (19) and 5-fluoro-α-glycosyl fluoride (20)
Page S-17: Scheme S-2
Electronic Supplementary Material (ESI) for Organic & Biomolecular Chemistry.This journal is © The Royal Society of Chemistry 2015
S-2
Page S-18: Fig. S-2. Reaction assembly set-up for photobromination of C5 position of glycosyl compounds
Page-S-19 to S-22: Experimentals for scheme S-21,2,3,4,6-penta-O-acetyl-α/β-D-glucopyranoside (15)2,3,4,6-penta-O-acetyl-α-D-glycosyl fluoride (16)2,3,4,6-penta-O-acetyl-5-bromo-α-D-glycosyl fluoride (17)2,3,4,6-O-acetyl-5-fluoro-β-D-idosyl fluoride (18)5-Fluoro-β-D-idosyl fluoride (19)5-Fluoro-α-D-glycosyl fluoride (20)
Pages S-23 to S-74: NMR Spectra
1H NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-2,3,6-tri-O-acetyl-α-D-glucopyranosyl bromide (9)13C NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-2,3,6-tri-O-acetyl-α-D-glucopyranosyl bromide (9)COSY of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-2,3,6-tri-O-acetyl-α-D-glucopyranosyl bromide (9)HMQC of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-2,3,6-tri-O-acetyl-α-D-glucopyranosyl bromide (9)1H NMR of 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-α-D-glycal (10)13C NMR of 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-α-D-glycal (10):COSY of 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-α-D-glycal (10)19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α/β-D-gluco-and D-mannopyranoses (11)19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-1,3,6-tri-O-acetyl-2-deoxy-2-fluoro-α/β-D-gluco-and D-mannopyranoses (12)19 F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-gluco/ D-mannopyranosyl bromide (13)1H NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-glycal (1) 13C NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-glycal (1)COSY of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-glycal (1) HMQC of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-glycal (1)19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-glycal (1) 1H NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-mannopyranosyl bromide (14)13C NMR attached protein test (APT) experiment of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-mannopyranosyl bromide (14)
S-3
COSY of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-mannopyranosyl bromide (14)HMQC of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-mannopyranosyl bromide (14)19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-mannopyranosyl bromide (14)1H NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (2)13 C NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (2)13C NMR (APT) of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (2)COSY of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (2)HMQC of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (2)19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (2) (Vxrs400 MHz)1H NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (3) 13 C NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (3)COSY of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (3)HMQC of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (3)19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (3) (Gemini 200MHz)1H NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α/β-D-glucopyranose (4) 13C NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α/β-D-glucopyranose (4)COSY of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α/β-D-glucopyranose (4)HMQC of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α/β-D-glucopyranose (4)19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α/β-D-glucopyranose (4)1H NMR of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (5)13C NMR of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (5)COSY of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (5)HMQC of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (5)
S-4
19F of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (5)1H NMR of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (6)13C NMR of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (6)COSY of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (6)HMQC of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (6)19F of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (6)1H NMR of compound 2,3,4,6-penta-O-acetyl-α-D-glycosyl fluoride (16)1H NMR of compound 2,3,4,6-penta-O-acetyl-5-bromo-α-D-glycosyl fluoride (17)1H NMR of compound 2,3,4,6-O-acetyl-5-fluoro-β-D-idosyl fluoride (18) 1H NMR of compound 5-fluoro-β-D-idosyl fluoride (19)19F-NMR of compound 5-fluoro-β-D-iodosyl fluoride (19) 1H-NMR of compound per-O-acetyl-5-fluoro-α-glycosyl fluoride (20)
Page S-75: References
S-5
Enzyme substrate assay for α-MTF
MALDI-MS was performed to evaluate α-MTF incorporation into maltooligosaccharides via Sco
GlgE-V279S and compared to a series of controls, (Fig S-1). The spectra of only maltohexaose
(M6) in buffer, showed a single peak representing a sodiated M6, Fig S-1A. The addition of Sco
GlgE1-V279S resulting in a series of higher molecular weight products which result from known
background transglycosylation activity catalyzed by Sco GlgE1-V279S, Fig S-1B. We also
prepared -maltosyl fluoride (-M1F), a substrate for Sco GlgE1. The use of M1F, M6 and Sco
GlgE1-V279S, Fig S-1C, resulted in higher molecular weight peaks. A final experiment replaced
M1F with α-MTF, which produced a spectrum identical to the control shown in Fig S-1B. Any
production of longer maltooligosaccharides would be the result of GlgE activity and those
products would have a molecular weight change resulting from the difluoromethylene unit.
S-6
Fig S-1. Evaluation of α-MTF as a substrate for Sco GlgEI-V279S. (A) control 1: ESI-MS of maltohexaose (M6). (B) control 2: ESI-MS of M6 + Sco GlgEI-V279S. (C) control 3: ESI-MS of M6 + Sco GlgEI-V279S + -M1F. (D) ESI-MS of M6 + Sco GlgEI-V279S + α-MTF. M4, M6, M8, M10, M12, and M14, represent 4, 6, 8, 10, 12, and 14 maltose units in the respective products. R = the continuation of the maltose repeat.
S-7
Synthesis of 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-
fluoro-glycal (1) and 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-
deoxy-2-fluoro-α-D-mannopyranosyl bromide (14)
Synthesis of Peracetylated glycal (10) was performed the methods of Braitsch et al.1 D-maltose 7
was peracetylated to obtain peracetyl maltose 8. Maltose derivative 8 was brominated at the
anomeric position using 33% hydrobromic acid in glacial acetic acid to obtain the corresponding
α-maltosyl bromide (9), Scheme S-1. Maltosyl bromide 9 was subjected to a zinc-mediated β-
elimination using activated zinc and N-methylimidazole to afford the glycal 10 in 53% yield.1
Glycal 10 was dissolved in DMF:H2O (3:1) and subjected to treatment with 1-(chloromethyl)-4-
fluoro-1,4-diazoniabicyclo[2.2.2]octane ditetrafluoroborate (Selectfluor®) to afford an anomeric
mixture of (α/β)-1-hydroxy-2-fluoro derivatives with gluco and manno (2:1 ratio, respectively)
stereochemistry 11.2 This mixture 11 was acetylated using Ac2O/Py. The resulting peracetylated
mixture 12 was treated with 33% hydrobromic acid in glacial acetic acid at 0 °C to afford a
mixture of 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-
α-D-gluco/ D-mannopyranosyl bromides (13). The mixture 13 was subjected to a second
elimination. Only the compound with gluco stereochemistry which has anti-periplanarity
between C1'-bromo group and the C2' hydrogen eliminated to afford per-O-acetyl-2-fluoro-
maltal (1).3, 4 This result was confirmed by isolating 2',3',4',6'-Tetra-O-acetyl-α-D-
glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-mannopyranosyl bromide (14)
while purifying glycal (1).
S-8
Scheme S-1. Synthesis of 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-glycal (1) and
2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-mannopyranosyl bromide (14).
O
RORO
RO
OR
O
ROROO
OR
OR
O
AcOAcO
AcO
OAc
O
AcOAcOO
OAc
Br
O
AcOAcO
AcO
OAc
OAcOO
OAc
O
AcOAcO
AcO
OAc
O
FAcOO
OAc
OR
11 R = H
12 R = Ac
O
AcOAcO
AcO
OAc
OAcOO
OAc
BrF
O
AcOAcO
AcO
OAc
OAcOO
OAc
F
b c
d b e
9 10
13
1
O
AcOAcO
AcO
OAc
OAcOO
OAc
Br
F
14
7 D-Maltose
8 R = Aca
a
Reagents and conditions: a) Ac2O, pyridine, rt (99%); b) 33% HBr in AcOH, dry CH2Cl2 (88%); c) Zinc, N-methylimidazole,
EtOAc, reflux (53%); d) Selectfluor®, DMF:H2O (3:1), rt (53%) (2:1); e) CH3CN, Et3N, reflux (30%).
S-9
2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-1,2,3,6-tetra-O-acetyl-α-D-
glucopyranose (8)1
To a solution of maltose monohydrate 7 (4.0 g, 11.1 mmol) in pyridine (12.5 mL, 133.2
mmol) was added acetic anhydride (14.3 mL, 178 mmol) drop wise at 0 C. The solution
was maintained at room temperature for 12 h. The pyridine was removed as an azeotrope
with toluene by repeated coevaporation. The resulting clear syrup was dissolved in ethyl
acetate and washed with 1 N HCl (25 mL) and saturated NaHCO3 solution (50.0 mL).
The organic layer was dried by passing through anhydrous Na2SO4. The solvent was
evaporated under vacuum to afford a clear white foam compound 8. Yield: 96% (7.2 g);
silica gel TLC Rf = 0.56 (1:1 hexane-acetone); 1H-NMR (600 MHz, CDCl3): δ 5.75 (d,
1H, 3J1,2 8.07 Hz, H-1), 5.42 (d, 1H, 3J1’,2’ 4.03 Hz, H-3'), 5.36 (dd, 1H, 3J3’,4’ 9.9 Hz,
3J3’,2’ 10.27 Hz, H-3’), 5.30 (dd, 1H, 3J3,2 9.17 Hz, 3J3,4 8.80 Hz, H-3), 5.06 (dd, 1H, 3J3’,4’
9.9 Hz, H-4'), 4.98 (dd, 1H, 3J2,3 8.80 Hz, H-2), 4.87 (dd, 1H, 3J2’,3’ 10.64 Hz, 3J3’,4’ 4.03
Hz, H-2'), 4.46 (dd, 1H, 2J6a,6b 12.10 Hz, 3J6a,5 1.83 Hz, H-6a), 4.26-4.22 (m, 2H, 6-a, 6-
b), 4.06-4.03 (m, 2H, 6’b, H-4), 3.95-3.93 (m, 1H, H-5’), 3.86-3.83 (m, 1H, H-5), 2.23 (s,
3H, CH3), 2.15 (s, 3H, CH3), 2.11 (s, 3H, CH3), 2.06 (s, 3H, CH3), 2.03 (s, 3H, CH3), 2.02
(s, 3H, CH3), 2.02 (s, 3H, CH3), 2.01 (s, 3H, CH3); 13C-NMR (600 MHz, CDCl3): 170.73
(C=O), 170.68 (C=O), 170.61 (C=O), 170.24 (C=O), 170.06 (C=O), 169.77 (C=O),
169.61 (C=O), 168.97 (C=O), 95.85 (C1'), 91.39 (C1), 75.40 (C3), 73.11 (C4), 72.50
(C5), 71.07 (C2), 70.13 (C2'), 69.43 (C3'), 68.71 (C5'), 68.06 (C4'), 62.64 (C6), 61.57
(C6'), 21.02 (CH3), 20.97 (2 CH3), 20.84 (CH3), 20.75 (3 CH3), 20.71 (CH3) ppm; mass
spectrum (ESIMS), m/z = 701.3 (M+23)+ C28H38O19 requires 701.19 (M+23)+.
S-10
2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-2,3,6-tri-O-acetyl-α-D-
glucopyranosyl bromide (9)1
Compound 8 (1.00 g, 1.47 mmol) was dissolved in dry methylene chloride (5.0 mL). To
the solution was added acetic acid (5.0 mL). The solution was cooled to 0 C 33% HBr in
acetic acid (1.0 mL, 2.76 mmol) was added by drop wise addition. The reaction was
maintained at 0 C for 4 h. Ice cold water was added and the solution extracted with DCM
(20.0 mL, 3 times). The combined DCM extracts were washed with cold distilled. H2O
and the organic layer dried over anhydrous Na2SO4. The solvent was removed under
reduced pressure to obtain a light yellow foam 9, which was sensitive to light. Yield:
88.2% (0.908 g); silica gel TLC Rf = 0.42 (6:4 Hexanes-Acetone). 1H-NMR (600 MHz,
CDCl3): δ 6.51 (d, 1H, 3J1,2 3.67 Hz, H-1), 5.63 (dd, 1H, 3J3,2 9.54 Hz, H-3), 5.44 (d, 1H,
3J1',2' 4.03 Hz, H-1'), 5.39 (dd, 1H, 3J3’,2’ 10.27 Hz, 3J3’,4’ 9.90 Hz, H-3), 5.09 (dd, 1H,
3J4’,3’ 9.90 Hz, H-4'), 4.88 (dd, 1H, 3J1’,2’ 4.03 Hz, 3J2’,3’ 10.64 Hz, H-2'), 4.73 (dd, 1H,
3J1,2 3.67 Hz, 3J2,3 9.90 Hz, H-2), 4.53 (dd, 1H, 2J6a,6b 13.94 Hz, 3J6a,5 4.55 Hz, H-6a),
4.29-4.25 (m, 3H, 6-a', 6-b, H-5), 4.10-4.05 (m, 2H, H-4, 6-b'), 3.96-3.95 (m, 1H, H-5'),
2.16 (s, 3H, CH3), 2.11 (s, 3H, CH3), 2.09 (s, 3H, CH3), 2.08 (s, 3H, CH3), 2.05 (s, 3H,
CH3), 2.04 (s, 3H, CH3), 2.02 (s, 3H, CH3) ppm; 13C NMR (CDCl3): 170.86 (C=O),
170.67 (C=O), 170.46 (C=O), 170.14 (2 C=O), 169.68 (C=O), 169.60 (C=O), 95.91 (C1'),
86.18 (C1), 72.66 (C5), 72.47 (C3), 71.64 (C4), 71.17 (C2), 70.15 (C2), 69.38 (C3'),
68.78 (C5), 68.01 (C4), 61.97 (C6), 61.45 (C6'), 21.03 (CH3), 20.95 (CH3), 20.86 (CH3),
20.81 (CH3), 20.77 (3 CH3) ppm; mass spectrum (ESIMS), m/z = 722.38 (M+23)+
C28H38O19 requires 722.44 (M+23)+.
S-11
2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-α-D-glycal (10)1
Compound 9 (2.10 g, 3.00 mmol) was dissolved in dry ethyl acetate (30 mL). To this
solution was added Zn powder (1.9 g, 30.0 mmol), and N-methylimidazole (377 mg, 4.60
mmol). The solution was stirred vigorously, heated to reflux, and maintained at that
temperature for 6 h. After the reaction was completed the Zn was removed by filtering
through Celite. The Celite was washed twice with EtOAc (15 mL) for complete
extraction. The filtrate was washed with saturated NaHSO4 (20 mL) followed by
NaHCO3 (20 mL), and the ethyl acetate layer was dried over anhydrous Na2SO4. The
dried ethyl acetate layer was concentrated under reduced pressure to obtain crude 10
which was purified by flash column chromatography on silica gel using a mobile phase of
25% acetone in hexanes. Compound 10 was obtained as a colorless solid. Yield: 53%
(0.891 g); silica gel TLC Rf = 0.44 (6:4 hexanes-acetone); 1H-NMR (600 MHz, CDCl3): δ
6.45 (d, 1H, 3J1,2 6.01 Hz, H-1), 5.52 (d, 1H, 3J1’,2’ 3.9 Hz, H-1'), 5.41 (dd, 1H, 3J3’,2’
10.01 Hz, H-3'), 5.18 (m, 1H, H-3), 5.07 (t, 1H, 3J3’,4’ 10.01 Hz, 3J4’,5’ 9.77 Hz, H-4'),
4.84-4.82 (m, 2H, H-2', H-2), 4.39 (dd,1H, 2J6a,6b 11.96 Hz, 3J6a,5 3.42 Hz, H-6a), 4.35
(dd, 1H, 2J6a,6b 12.21 Hz, 3J6a,5 5.62 Hz, H-6b), 4.31-4.29 (m, 1H, H-5), 4.25 (dd, 2J6’a,6’b
12.45, 3J6a,5 3.91 Hz, 1H, H-6'a), 4.10 (dd, 1H, 2J6’a,6’b 12.45 Hz, 3J6a,5 1.71 Hz, H-6'b),
4.06-4.02 (m, 2H, H-4, H-5'), 2.13 (s, 3H, CH3), 2.11 (s, 3H, CH3), 2.06 (s, 3H, CH3),
2.05 (s, 3H, CH3), 2.04 (s, 3H, CH3), 2.02 (s, 3H, CH3) ppm; 13C NMR (CDCl3): δ 170.8
(C=O), 170.71 (C=O), 170.71 (C=O), 170.61 (C=O), 170.26 (C=O), 170.78 (C=O),
145.78 (C1), 98.83 (C2), 95.97 (C1'), 74.25 (C5), 72.60 (C4), 70.59 (C2'), 69.826 (C3'),
69.82 (C3'), 69.74 (C3), 68.43 (C5'), 68.29 (C4), 62.03 (C6), 61.77 (C6'), 21.32 (CH3),
S-12
21.03 (CH3), 20.91 (CH3), 20.89 (CH3), 20.83 (CH3), 20.77 (CH3) ppm; mass spectrum
(ESIMS), m/z = 583.3 (M+23)+ C24H32O16 requires 583.49 (M+23)+.
2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-
α/β-D-gluco-and D-mannopyranoses (11)2
To a solution of compound 10 (1.22 g, 2.17 mmol) in DMF (15.0 mL) was added H2O
(5.0 mL). The reagent Selectfluor® (1.90 g, 5.41 mmol) was added to the solution in two
proportions. The second portion was added after 4 h of maintenance of the reaction at
room temperature. The reaction was allowed to stir an additional 12 h at room
temperature. The solution was diluted with EtOAc (60 mL) and washed with cold H2O
(50 mL 3 times). The organic layer was dried over anhydrous Na2SO4 and the solvent was
evaporated under reduced pressure to obtain a light yellow syrup. The crude product was
purified by flash column chromatography on silica gel by elution with acetone-hexanes
(2:3). This yielded a mixture of compounds, (α/β)-1-hydroxy-2-fluoro derivatives, with
gluco and manno stereochemistry 11. Yield: 54% (695.0 mg); silica gel TLC Rf = 0.31
(6:4 hexanes -acetone); crude product used for next step without purification; mass
spectrum (ESIMS), m/z = 619.25 (M+23)+ C24H33FO16 requires 619.16 (M+23)+.
2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-1,3,6-tri-O-acetyl-2-deoxy-2-
fluoro-α/β-D-gluco-and D-mannopyranoses (12)
To a solution compounds 11 (694 mg, 1.16 mmol) in pyridine was added acetic anhydride
(329 L, 3.49 mmol). The solution was maintained at room temperature for 8 h. The
reaction was concentrated by evaporating the pyridine under reduced pressure to obtain
S-13
an oily liquid. This residue was diluted with EtOAc (20 mL). The EtOAc layer was
washed with 0.5 N HCl (15 mL), followed by water (20 mL), and brine (20 mL). The
organic layer dried over anhydrous Na2SO4 and the solvent evaporated under reduced
pressure to obtain a colorless foam 12 as a mixture of α/β-2-fluoro derivatives with gluco
and manno stereochemistry 12 (2.2:1, respectively). Yield: 99% (742 mg); silica gel TLC
Rf = 0.48 (2:3 acetone-hexanes), the obtained compound was used in next step without
purification; 19F-NMR (Vxrs400 MHz, CDCl3): 2-fluro gluco derivative: δ -203.3 (dd,
2JF,2 48.84 Hz, JF,3 12.21 Hz, F-2a); 2-fluoro manno derivative: δ -204.75 (ddd, 2JF,2 48.83
Hz, 3JF,3 27.47 Hz, 3JF,1 7.64 Hz, F-2e) ppm; mass spectrum (ESIMS), m/z = 661.18
(M+23)+ C26H35FO17 requires 661.17 (M+23)+.
2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-
α-D-gluco-and D-mannopyranosyl bromide (13)
The mixture of compounds 12 (784 mg, 1.23 mmol) was dissolved in methylene chloride
(3.5 mL) and the solution was cooled to 0 C. To the solution was added 33% HBr in
acetic acid (4.5 mL) by drop-wise addition. The reaction was maintained at 18 C for 8 h.
After the reaction was complete, the solution was diluted with cold H2O and extracted
three times with DCM (25 mL). The organic layers were combined and washed with H2O
(15 mL), brine (15 mL), and dried over anhydrous Na2SO4. The solvent was evaporated
under reduced pressure to obtain a colorless foam 13 as a mixture of α-1-bromo-2-fluoro
derivatives with gluco and manno stereochemistry. Yield: 98% (807.0 mg); The crude
material was used for next step without purification; 19F-NMR of compounds α-bromo-2-
fluoro derivatives with gluco and manno stereochemistry: δ -183 (m, F-2), -190.5 (m, F-
S-14
2) ppm; mass spectrum (ESIMS), m/z = 681.09 (M+23)+ C24H32BrFO15 requires 681.08
(M+23)+.
2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-
glycal (1)4
Mixture 13 (808 mg, 1.23 mmol) was dissolved in acetonitrile (10.0 mL) and
triethylamine (304 µL, 3.68 mmol) was added. The reaction mixture was heated to 65-70
C for 6 h. The solution was concentrated under reduced pressure and purified by gravity
column chromatography on silica gel using a mobile phase consisting of 7% acetone in
DCM to obtain pure compound 1. Yield: 33% (230.0 mg); silica gel TLC Rf = 0.19 (3:97
acetone-dichloromethane), and compound 14. Yield: 30% (207.0 mg); silica gel TLC Rf
= 0.28 (3:97 acetone-dichloromethane); (1): 1H-NMR (600 MHz, CDCl3): δ 6.77 (d, 1H,
3J1,2 4.77 Hz, H-1), 5.44-5.41 (m, 2H, H-1', H-3'), 5.37 (dd, 1H, 3J3,4 5.87 Hz, 3J3,1 1.47
Hz, H-3), 5.05 (t, 1H, 3J3,4 9.9 Hz, H-4'), 4.85 (dd, 1H, 3J2',3' 10.27 Hz, 3J2',1' 4.03 Hz, H-
2'), 4.47 (m, 1H, H-5), 4.37 (dd, 1H, 2J6a,6b 11.74 Hz, 3J6a,5 7.70 Hz, H-6a), 4.20 (dd, 1H,
2J6'a,6'b 12.47 Hz, 3J6'a,5' 4.77 Hz, H-6a'), 4.16 (dd, 1H, 2J6a,6b 11.74 Hz, 3J6b,5 4.4 Hz, H-
6b), 4.13 (dd, 1H, 2J6'b,6'a 12.47 Hz, 3J6'b,5' 2.20 Hz, H-6b'), 4.09-4.06 (m, 1H, H-5), 4.00-
3.98 (m, 1H, H-4), 2.11 (s, 3H, CH3), 2.10 (s, 3H, CH3), 2.04 (s, 3H, CH3), 2.03 (s, 3H,
CH3) ppm; 13C-NMR (CDCl3): δ 170.59 (C=O), 170.47 (C=O), 170.31 (C=O), 170.68
(C=O), 169.97 (C=O), 169.59 (C=O), 142.12 (d, 1J2,2F 239.99 Hz, C2), 132.09 (d, 2J1,2F
39.61 Hz, C1), 96.88 (C1'), 74.50 (d, 3J4,2F 7.70 Hz, C4), 73.99 (C5), 70.54 (C2'), 69.87
(C3'), 68.38 (C4', C5'), 65.79 (d, 2J3,2F 23.11 Hz, C3), 61.91 (C6'), 60.62 (C6), 20.76 (s,
6H, 2 CH3), 20.71 (s, 3H, CH3), 20.68 (s, 3H, CH3), 20.62 (s, 3H, CH3), 20.55 (s, 3H,
S-15
CH3) ppm; 19F NMR (Vxrs400 MHz, CDCl3): δ -164.51 (dd ,1F, 3JF,1 6.11 Hz, 3J3,F 4.58
Hz, F-2) ppm; mass spectrum (ESIMS), m/z = 601.14 (M+23)+ C24H33FO16 requires
601.15 (M+23)+.
2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-
α-D-mannopyranosyl bromide (14)
1H-NMR (600 MHz, CDCl3): δ 6.37 (d, 1H, 3J1,2 9.54 Hz, H-1), 5.57 (d, 1H, 3J1',2' 4.04 Hz, H-1'),
5.54 (dd, 1H, 3J3,F 26.04 Hz, 3J3,4 9.54 Hz, 3J3,2 2.20 Hz, H-3), 5.40 (t, 1H, 3J3’4’ 9.90 Hz, H-3'),
5.10 (t, 1H, 3J3'4' 9.90 Hz, H-4'), 4.95 (d, 1H, 2JF,2 48.78 Hz, H-2), 4.89 (dd, 1H, 3J2’3’ 11.00 Hz,
3J2'1' 4.03 Hz, H-2'), 4.52 (dd, 1H, 2J6a,6b 12.47 Hz, 3J6a,5 1.83 Hz, H-6a), 4.32-4.29 (m, 2H, H-4,
H-6b), 4.27 (dd, 1H, 2J6'a,6'b 12.47 Hz, 3J6'a,5' 3.30 Hz, H-6a), 4.20-4.18 (m, 1H, H-5), 4.08 (dd,
1H, 2J6'a,6'b 12.47 Hz, 3J6'b,5' 2.20 Hz, H-6b'), 3.99-3.97 (m, 1H, H-5') ppm; 13C-NMR (CDCl3): δ
170.70 (C=O), 170.57 (C=O), 170.51 (C=O), 170.17 (C=O), 170.12 (C=O), 169.61 (C=O), 95.98
(C1'), 88.59 (dd, 1J2F,2 185.76 Hz, C2), 82.16 (d, 2J2F,1 26.14 Hz, C1), 72.98 (C5), 71.99 (C3),
71.88 (C2), 70.38 (C2'), 69.50 (C3'), 69.46 (C4), 68.74 (C5'), 68.03 (C4'), 62.03 (C5'), 61.49
(C6'), 21.07 (CH3), 20.91 (CH3), 20.84 (CH3), 20.78 (CH3), 20.75 (CH3), 20.67 (CH3) ppm; 19F
NMR: δ -183 (m, F-2 ) ppm; m/z = 681.0806 (M+Na)+, C6H10F2O5 requires 658.0909.
S-16
Synthesis of 5-fluoro-β-D-idosyl fluoride (19): 5-Fluoro-glycosyl fluorides have also been
reported to inhibit of glycoside hydrolases.5 We synthesized 5-fluoro-β-idosyl fluoride (19) and
trace 5-fluoro-α-glycosyl fluoride (20). 6, 7 We envisioned fluoride 19 as a key intermediate on
route to fluoride 20, Scheme S-2. The known approach to access C5' fluoro glycosides has been
to photo-brominate the C5' position of the glycoside followed by displacement of the bromide
using a fluoride source.8, 9 We explored the photo-bromination of per-O-acetyl-α-glycosyl
fluoride (16) to access 2,3,4,6-tetra-O-acetyl-5-bromo-1-fluoro-α-glycosyl fluoride (17) (Figure
S-2). Glycosyl fluoride 17 was treated with AgF or AgBF4; however, only undesired epimeric
2,3,4,6-tetra-O-acetyl-5-fluoro-β-L-idosyl fluoride 18 was formed.8-10 We investigated methods
for equilibrating 18 to the D-gluco configuration 20. We examined: i) longer reaction times, ii)
higher tempratures, and iii) addition of HF-pyridine to equilibriate the L-idosyl fluoride 18 to the
D-glucosyl fluoride 20.9 However, these efforts did not prove to be helpful in our case. Other
strategies to epimerize from the L-idose to the D-glucose configuration were to treat the L-idosyl
fluoride with Lewis acids e.g., i) BF3.OEt2, ii) BF3.OEt2 + TMSOTf, iii) BF3.OEt2 + HF-
pyridine, and iv) Cp2(Zr)Cl2 + AgOTf, respectively. 9, 11-13 BF3.OEt2 worked with trace yields in
our hands to produce the 2,3,4,6-tetra-O-acetyl-5-fluoro-α-glycosyl fluoride (20) in an equilbium
favoring starting material 18.6 Fluoride 18 was deacetylated with NH3-MeOH to afford 19. Since
we could only produce 20 in only trace ammounts and since the structure of the GlgE 2-deoxy-2-
fluoro-α-maltosyl fluoride (α-MDF) in complex with Sco GlgEI-E423A14 was reported, there
was no need to further pursue this target. Our reaction apparatus description and detailed
conditions to produce 17 may be helpful to other researchers.
S-17
Scheme S-2. Synthesis of 2,3,4,6-tetra-O-acetyl-5-fluoro-β-D-idosyl fluoride (19) and 2,3,4,6-
tetra-O-acetyl-5-fluoro-α-glycosyl fluoride (20)
O
18
AcO
OAc
F
OAc
OAcF
OAcOAcO
AcO
OAc
OAc
OAcOAcO
AcO
OAc
F
O
19
HO
OH
F
OH
OHF
15 16 17
OAcOAcO
AcO
OAc
FBr
a b
dc
20
e OAcOAcO
AcO
OAc
FF
Reagents and conditions: a) HF-Pyridine, 83 %; b) N-bromosuccinamide, AIBN, CCl4, 2x250W
flood lamp (50 %); c) AgF, CH3CN (68 %); d) NH3-MeOH, quantitative; e) BF3.OEt2 (low).
S-18
Figure S-2. Reaction assembly set-up for photobromination of C5 position of glycosyl compounds
S-19
1,2,3,4,6-penta-O-acetyl-α/β-D-glucopyranoside (15):15 Compound 15 (10.0 g, 0.055 mol),
was dissolved in pyridine (48.2 g, 0.61 mol) and acetic anhydride (62.2 g, 0.61 mol). DMAP (10
mg) was added to the reaction flask and reaction stirred for a period of 4 h. Completion of the
reaction was monitored by TLC using ethyl acetate-hexanes (3:7). The reaction was concentrated
under reduced pressure to obtain colorless residue. The residue was dissolved in toluene and
concentrated under reduced pressure to remove most of the pyridine and residual acetic acid
generated during the reaction. The residue was diluted with ethyl acetate and was washed with 1
N HCl followed by saturated aqueous sodium bicarbonate. The organic layer was dried over
anhydrous Na2SO4 and concentrated under reduced pressure. The crude material 15 was obtained
as white amorphous solid. Yield: 99% (21.0 g). The characterization data for compound 15
matches the previously reported data.
2,3,4,6-penta-O-acetyl-α-D-glycosyl fluoride (16)16 HF-pyridine (~70% hydrogen fluoride in
~30% pyridine) (15 mL) was added to compound 15 (2.0 g, 5.1 mmol) in a polypropylene tube.
The mixture was stirred to dissolution at room temperature. The reaction was further stirred for 7
h. Completion of the reaction was monitored by TLC using hexanes-acetone (6:4). The reaction
was diluted with excess of dichloromethane. The solution was neutralized with saturated aqueous
sodium bicarbonate cooled over an ice-bath. The organic layer was extracted with saturated
aqueous sodium bicarbonate solution (3 × 100 mL) to remove residual acid. The organic layer
was dried over anhydrous MgSO4 and concentrated under reduced pressure. The crude material
was purified using flash column chromatography on silica gel using 25% acetone in hexanes to
obtain α-glucosyl fluoride, compound 16 as white amorphous solid. Yield: 75% (1.32 g); silica
gel TLC Rf = 0.50 (99:2 ethyl acetate-dichloromethane). The characterization data for compound
S-20
16 matches the previously reported data; 1H NMR (600 MHz, CD3OD): δ (600 MHz, CDCl3)
5.76 (dd, 1H, 2JH1,F = 53.4 Hz, 3JH1,H2 = 2.4Hz, H-1), 5.49 (m, 1H, H-3), 5.15 (m, 1H, H-4), 4.95
(dddd, 1H, 3JH2,F = 24 Hz, 3JH2,H3 = 10.2 Hz, 3JH2,H1 = 2.4 Hz, H-2), 4.29 (dd, 1H, 3JH6a,H5 = 12.6
Hz, 3JH6a,H6b = 3.6 Hz, H-6a), 4.19 (m, 1H, H-5), 4.15 (dd, 1H, 3JH6b,H5 = 12.6 Hz, 3JH6a,H6b = 2.4
Hz, H-6b), 2.11 (s, 3H, CH3), 2.10 (s, 3H, CH3), 2.04 (s, 3H, CH3), 2.03 (s, 3H, CH3) ppm; mass
spectrum (ESIMS), m/z = 373.09 (M+23)+ C14H19FO9 requires 373.09 (M+23)+.
2,3,4,6-penta-O-acetyl-5-bromo-α-D-glycosyl fluoride (17)8 Compound 16 (1.80 g, 5.14
mmol) was stirred in 80.0 mL anhydrous CCl4 at room temperature, in a quartz flask attached to
a reflux assembly under nitrogen atmosphere. N-Bromosuccinimide (3.65 g, 20.6 mmol) and
AIBN (83 mg, 0.51 mmol) was added to the reaction vessel. The reaction was stirred under
refluxing conditions using 2x250 Watts (120V) heat lamps stationed at a distance of 3.0 cm on
either side of the reaction vessel. Completion of reaction was monitored using 1H-NMR and TLC
using ethyl acetate: dichloromethane (0.2:9.9). The reaction was stirred under reflux for 18.0 h.
The reaction was concentrated under reduced pressure to obtain a brown colored residue. The
residue was diluted with dichloromethane (100 mL) and washed sequentially with water (1 × 50
mL), saturated sodium bicarbonate (1 × 50 mL) and brine solution (1 × 50 mL). The organic
layer was dried over anhydrous MgSO4 and concentrated under reduced pressure. The crude
material was purified using silica gel flash column chromatography using 1 % ethyl acetate in
dichloromethane to obtain 5-bromo-α-glucosyl fluoride, compound 17. Yield: 47% (1.03 g);
silica gel TLC Rf = 0.55 (99:2 ethyl acetate-dichloromethane). The characterization data for
compound 17 matches the previously reported data. 1H NMR (600 MHz, CD3OD): δ 5.93 (dd,
1H, 2JH1,F = 52.8 Hz, 3JH1,H2 = 3.0 Hz, H-1), 5.86 (t, 1H, H-3), 5.21 (d, 1H, 3JH4,H3 = 10.2 Hz, H-
S-21
4), 5.06 (dddd, 1H, 3JH2,F = 24 Hz, 3JH2,H3 = 10.8 Hz, 3JH2,H1 = 3.6 Hz, H-2) 4.43 (dd, 2H, H-
6a,H-6b), 2.13 (s, 3H, CH3), 2.12 (s, 3H, CH3), 2.10 (s, 3H, CH3) 2.05 (s, 3H, CH3) ppm; mass
spectrum (ESIMS), m/z = 451.00 (M+23)+ C14H18BrFO9 requires 451.00 (M+23)+.
2,3,4,6-O-acetyl-5-fluoro-β-D-idosyl fluoride (18):8 Compound 17 (1.0 g, 2.2 mmol) was
dissolved in 15 mL of anhydrous acetonitrile under nitrogen atmosphere. The reaction flask was
covered with aluminum foil and the reaction carried out in the dark. Silver (I) fluoride (0.70 g,
5.5 mmol) was added to the flask under nitrogen atmosphere and the reaction stirred at room
temperature. The reaction was stirred for 4 h. Completion of the reaction was monitored by TLC
using ethyl acetate-hexane (3:97). The reaction was filtered and the filtrate was concentrated
under reduced pressure to obtain a light brown residue. The residue was dissolved in ethyl
acetate (50 mL) and washed sequentially with water (1 × 50 mL) and brine solution (1 × 50 mL).
The organic layer was dried over anhydrous MgSO4 and concentrated under reduced pressure.
The crude material was purified using silica gel flash column chromatography using 1 % ethyl
acetate in diethyl ether to obtain 5-fluoro-β-L-idosyl fluoride, compound 18. Yield: 68% (0.55
g); silica gel TLC Rf = 0.38 (3:97 ethyl acetate-hexanes). 1H NMR (600 MHz, CD3OD): δ 5.78
(d, 1H, 2JF,1H = 60.04, H-1), 5.39 (dd, 1H, 3JH2,F = 30.0 Hz, 3JH2,H3 = 12.0 Hz, H-2), 5.28 (m, 2H,
H-3, H-4), 4.43 (dd, 2H, 2JH6a,H6b = 24.0 Hz, 3JH6a,H5 = 12.0 Hz, H-6a), 4.18 (t, 1H, 2JH6a,H6b =
24.0 Hz, H-6b), 2.13 (s, 3H, CH3), 2.12 (s, 6H, 2CH3), 2.09 (s, 3H, CH3) ppm; mass spectrum
(ESIMS), m/z = 391.07 (M+23)+ C14H18F2O9 requires 391.08 (M+23)+.
5-Fluoro-β-D-idosyl fluoride (19):6 Compound 18 (8.6 mg) was dissolved in MeOH (1.5 mL)
and the reaction mixture was cooled to -10 C using dry ice in acetone. Ammonia gas was
S-22
bubbled into the solution for 10 min. The outlet of the reaction apparatus was connected to a bent
finger trap cooled to -78 C to trap any escaping ammonia gas. The reaction was maintained at
room temperature for 2 h. The reaction was concentrated to obtain an oily liquid of crude
compound 19, the crude compound was dissolved in minimum amount of H2O purified by C-18
chromatography (2% methanol in H2O), to obtain pure compound 19. 1H NMR (600 MHz,
CD3OD): δ 5.65 (d, 1H, 2JF,1H = 56.12, H-1), 3.93 (m, 1H, H-2), 3.78 (m, 3H), 3.66 (m, 1H) ppm;
mass spectrum (HRMS), m/z = 223.0401 (M+Na)+, C6H10F2O5 requires 223.0394 (M+Na)+.
5-Fluoro-α-D-glycosyl fluoride (20):17 Compound 19 (69.0 mg, 188 µM) was dissolved in
anhydrous CH2Cl2 (1.0 mL) under nitrogen atmosphere. The solution was cooled to 0 C and
BF3.OEt2 (0.007 mL) was added. The reaction was maintained at 0 C for another 10 minutes and
allowed to room temperature. The progress of reaction was monitored by 1H NMR. After 4 h
reaction was complete. The reaction was quenched with saturated aqueous NaHCO3 (5.0 mL).
The product was extraced from the aqueous layer by CH2Cl2 (5.0 mL). The organic layer was
washed with brine and dried over anhydrous MgSO4. The CH2Cl2 layer was concentrated under
reduced pressure and purifed by flash column chromatography on silica gel using 5% ethyl
acetate in dichloromethane as an eluent. The product was obtaind as mixture with 5-fluoro-β-D-
idosyl fluoride (19) and (20). 1H NMR (600 MHz, CD3OD): δ 5.85 (d, 1H, 2JF,1H = 53.0, H-1), 5.0
(dd, 1H, 3JH2,F = 24.0 Hz, H-2), 5.77 (t, 1H, 3JF,2H = 10.2, H-3), 5.23 (dd, 1H, 3JH4,F5 = 22.2 Hz,
H-4), 4.3 (dd, 1H, 2JH6a,H6b = 12.0 Hz, H-6a), 4.0 (dd, 1H, 2JH6a,H6b = 12.3 Hz, H-6b); mass
spectrum (ESIMS), m/z = 391.27 (M+Na)+, C6H10F2O5 requires 391.27 (M+Na)+.
S-23
1H NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-2,3,6-tri-O-acetyl-α-D-glucopyranosyl bromide (9):
9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5Chemical Shift (ppm)
2.983.093.063.093.023.123.071.072.043.351.031.011.151.141.141.061.011.01
TMS2.02
2.04
2.05
2.08
2.09
2.11
2.16
3.95
4.07
4.08
4.25
4.25
4.27
4.29
4.53
4.54
4.72
4.74
4.88
4.89
4.89
5.09
5.37
5.39
5.43
5.44
5.63
6.51
6.52
7.27
S-24
13C NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-2,3,6-tri-O-acetyl-α-D-glucopyranosyl bromide (9)
S-25
COSY of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-2,3,6-tri-O-acetyl-α-D-glucopyranosyl bromide (9)
S-26
HMQC of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-2,3,6-tri-O-acetyl-α-D-glucopyranosyl bromide (9)
S-27
S-28
1H NMR of 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-α-D-glycal (10)
9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5Chemical Shift (ppm)
3.073.046.073.043.103.151.041.072.012.011.040.940.980.950.94
TMS2.02
2.04
2.05
2.06
2.11
2.13
4.04
4.05
4.11
4.11
4.35
4.36
4.38
4.38
4.82
4.82
4.82
4.83
4.84
4.84
5.07
5.18
5.41
5.51
5.52
6.44
6.45
S-29
13C NMR of 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-α-D-glycal (10):
192 184 176 168 160 152 144 136 128 120 112 104 96 88 80 72 64 56 48 40 32 24 16 8 0Chemical Shift (ppm)
S-30
COSY of 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-α-D-glycal (10)
6.5 6.0 5.5 5.0 4.5 4.0 3.5F2 Chemical Shift (ppm)
4.0
4.5
5.0
5.5
6.0
6.5
F1 C
hem
ical
Shi
ft (p
pm)
S-31
19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α/β-D-gluco-and D-mannopyranoses (11)
-80 -100 -120 -140 -160 -180 -200 -220 -240 -260 -280 -300 -320 -340Chemical Shift (ppm)
-205
.08
-204
.96
-204
.88
-204
.74
-200
.57
-200
.43
-200
.40
S-32
19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-1,3,6-tri-O-acetyl-2-deoxy-2-fluoro-α/β-D-gluco-and D-mannopyranoses (12)
-32 -40 -48 -56 -64 -72 -80 -88 -96 -104 -112 -120 -128 -136 -144 -152 -160 -168 -176 -184 -192 -200 -208 -216 -224 -232Chemical Shift (ppm)
-204
.84
-204
.71
-204
.64
-203
.38
-203
.25
-203
.23
-201
.63
-201
.53
S-33
19 F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-gluco-and D-mannopyranosyl bromide (13)
20 10 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 -150 -160 -170 -180 -190 -200 -210 -220ppm
S-34
1H NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-glycal (1)
9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5Chemical Shift (ppm)
3.003.032.828.771.081.213.281.051.040.991.021.022.100.95
2.03
2.04
2.10
2.11
2.11
4.00
4.14
4.14
4.16
4.17
4.19
4.20
4.37
4.39
4.84
4.84
4.85
4.86
5.05
5.06
5.41
5.42
5.42
5.44
6.77
6.77
S-35
13C NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-glycal (1)
190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0ppm
S-36
COSY of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-glycal (1)
S-37
HMQC of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-glycal (1)
S-38
19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-glycal (1)
0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 -150 -160 -170 -180 -190 -200 -210 -220ppm
S-39
1H NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-mannopyranosyl bromide (14)
9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5Chemical Shift (ppm)
2.993.032.993.002.953.041.021.061.023.201.031.540.501.031.020.521.531.00
2.03
2.04
2.06
2.11
2.14
2.16
2.18
2.20
3.99
4.09
4.26
4.26
4.29
4.31
4.31
4.32
4.51
4.52
4.88
4.89
4.90
4.91
5.08
5.10
5.38
5.40
5.56
5.57
6.37
6.39
7.27
S-40
13C NMR attached protein test (APT) experiment of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-mannopyranosyl bromide (14)
S-41
COSY of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-mannopyranosyl bromide (14)
S-42
HMQC of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-mannopyranosyl bromide (14)
S-43
19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2-fluoro-α-D-mannopyranosyl bromide (14)
20 10 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 -150 -160 -170 -180 -190 -200 -210 -220ppm
S-44
1H NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (2)
9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5Chemical Shift (ppm)
2.972.992.852.996.011.011.044.120.971.011.011.030.961.000.97
1.57
2.02
2.04
2.08
2.11
2.17
2.18
3.95
4.08
4.09
4.19
4.25
4.25
4.27
4.27
4.60
4.86
4.86
4.88
4.88
5.09
5.11
5.34
5.36
5.45
5.46
5.48
5.62
S-45
13 C NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (2)
192 184 176 168 160 152 144 136 128 120 112 104 96 88 80 72 64 56 48 40 32 24 16 8 0 -8Chemical Shift (ppm)
101.
7210
1.96
102.
2010
3.26
103.
5010
3.74
112.
0011
2.24
113.
6611
3.90
115.
3411
5.59
S-46
13C NMR (APT) of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (2)
S-47
COSY of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (2)
S-48
HMQC of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (2)
S-49
19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (2) (Vxrs400 MHz)
8 0 -8 -16 -24 -32 -40 -48 -56 -64 -72 -80 -88 -96 -104 -112 -120 -128 -136 -144 -152 -160 -168 -176 -184 -192
Chemical Shift (ppm)
0.470.462.03
-14
8.3
8-1
48
.24
-12
2.6
1-1
22
.58
S-50
1H NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (3)
9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0
Chemical Shift (ppm)
3.133.113.013.313.122.921.071.041.091.092.411.001.081.181.041.151.570.48
CHLOROFORM-d 2.03
2.04
2.07
2.11
2.15
2.18
3.97
4.10
4.10
4.20
4.23
4.25
4.25
4.27
4.84
4.85
4.86
4.86
5.08
5.10
5.38
5.39
5.42
5.43
5.44
S-51
13 C NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (3)
190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0ppm
S-52
COSY of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (3)
S-53
HMQC of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (3)
S-54
19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (3) (Gemini 200MHz)
8 0 -8 -16 -24 -32 -40 -48 -56 -64 -72 -80 -88 -96 -104 -112 -120 -128 -136 -144 -152 -160 -168 -176 -184 -192
Chemical Shift (ppm)
1.011.001.01
-14
3.1
6-1
43
.09
-14
2.8
8
-12
8.6
2-1
27
.21
-11
5.5
0-1
14
.13
-11
4.0
8
S-55
1H NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro- α/β-D-glucopyranose (4)
9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5Chemical Shift (ppm)
2.983.113.043.025.960.721.011.281.033.591.021.181.241.031.261.050.99
2.02
2.04
2.07
2.11
2.16
3.78
3.99
4.08
4.09
4.14
4.25
4.26
4.55
4.86
4.87
4.88
4.88
5.07
5.09
5.10
5.36
5.37
5.39
5.45
5.46
5.66
5.68
S-56
13C NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro- α/β-D-glucopyranose (4)
S-57
COSY of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro- α/β-D-glucopyranose (4)
S-58
HMQC of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro- α/β-D-glucopyranose (4)
S-59
19F NMR of compound 2',3',4',6'-Tetra-O-acetyl-α-D-glucopyranosyl-(1,4)-3,6-di-O-acetyl-2-deoxy-2,2-difluoro- α/β-D-glucopyranose (4)
0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 -150 -160 -170 -180 -190 -200 -210Chemical Shift (ppm)
2.00
-182
.57
-182
.44
-182
.34
S-60
1H NMR of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (5)
9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5Chemical Shift (ppm)
1.171.091.102.275.541.031.020.490.49
3.32
3.33
3.33
3.46
3.47
3.48
3.62
3.67
3.68
3.89
3.90
3.92
4.22
4.25
4.26
4.88
4.91
4.93
5.32
5.33
5.59
5.60
5.68
5.68
S-61
13C NMR of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (5)
192 184 176 168 160 152 144 136 128 120 112 104 96 88 80 72 64 56 48 40 32 24 16 8 0Chemical Shift (ppm)
S-62
COSY of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (5)
S-63
HMQC of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (5)
S-64
19F of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-α-D-glucopyranosyl fluoride (5)
20 0 -20 -40 -60 -80 -100 -120 -140 -160 -180 -200 -220 -240Chemical Shift (ppm)
S-65
1H NMR of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (6)
9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0Chemical Shift (ppm)
1.091.051.053.043.121.021.051.000.500.49
3.29
3.29
3.30
3.30
3.33
3.57
3.63
3.63
3.64
3.65
3.82
3.84
4.04
4.09
4.87
4.90
5.26
5.27
5.40
5.42
5.49
5.51
S-66
13C NMR of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (6)
220 210 200 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 -10 -20Chemical Shift (ppm)
S-67
COSY of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (6)
S-68
HMQC of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (6)
S-69
19F of compound α-D-glucopyranosyl-(1,4)-2-deoxy-2,2-difluoro-β-D-glucopyranosyl fluoride (6)
20 0 -20 -40 -60 -80 -100 -120 -140 -160 -180 -200 -220 -240Chemical Shift (ppm)
S-70
1H NMR of compound 2,3,4,6-penta-O-acetyl-α-D-glycosyl fluoride (16)
9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0Chemical Shift (ppm)
3.062.875.962.071.041.010.991.000.520.51
TMS2.03
2.05
2.11
4.14
4.14
4.16
4.16
4.20
4.28
4.29
4.30
4.31
4.95
5.14
5.16
5.17
5.48
5.50
5.52
5.71
5.71
5.80
5.80
S-71
1H NMR of compound 2,3,4,6-penta-O-acetyl-5-bromo-α-D-glycosyl fluoride (17)
9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5Chemical Shift (ppm)
3.032.953.043.102.021.061.011.470.44
2.06
2.11
2.12
2.14
4.36
4.38
4.42
4.44
5.04
5.05
5.06
5.08
5.09
5.10
5.21
5.23
5.85
5.87
5.88
5.89
5.97
5.97
S-72
1H NMR of compound 2,3,4,6-O-acetyl-5-fluoro-β-D-idosyl fluoride (18)
9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5Chemical Shift (ppm)
2.922.836.002.091.051.031.000.980.510.50
TMS2.03
2.05
2.11
2.11
4.14
4.16
4.16
4.18
4.20
4.28
4.29
4.30
4.31
4.95
5.14
5.16
5.17
5.48
5.50
5.52
5.71
5.71
5.80
5.80
S-73
1H NMR of compound 5-fluoro-β-D-idosyl fluoride (19)
9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5Chemical Shift (ppm)
1.002.800.970.430.42
3.31
3.31
3.66
3.67
3.69
3.79
3.80
3.81
3.90
3.93
3.93
3.96
4.70
5.60
5.70
S-74
19F-NMR of compound 5-fluoro-β-D-iodosyl fluoride (19)
0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 -150 -160 -170 -180 -190 -200 -210Chemical Shift (ppm)
1.011.00
-139
.64
-139
.58
-139
.51
-139
.35
-139
.21
-139
.14
-112
.69
-112
.59
-112
.54
S-75
1H-NMR of compound per-O-acetyl-5-fluoro-α-glycosyl fluoride (20)
9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5Chemical Shift (ppm)
3.052.913.373.920.761.010.731.090.831.00
TMS2.05
2.12
2.13
2.14
4.07
4.07
4.09
4.09
4.30
4.31
4.32
4.33
5.04
5.06
5.10
5.30
5.31
5.33
5.35
5.76
5.78
5.80
5.81
5.81
5.89
5.90
S-76
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Beilstein J. Org. chemistry, 2012, 8, 448-455.2. M. D. Burkart, Z. Zhang, S. Hung and C. Wong, J. Am. Chem. Soc., 1997, 119, 11743-
11746.3. E. Boyd, R. V. H. Jones, P. Quayle and A. J. Waring, Tetrahedron Lett., 2006, 47, 7983-
7986.4. R. Zhang, J. D. McCarter, C. Braun, W. Yeung, G. D. Brayer and S. G. Withers, J. Org.
Chem., 2008, 73, 3070-3077.5. H. J. Rozeboom, S. Yu, S. Madrid, K. H. Kalk, R. Zhang and B. W. Dijkstra, J. Biol.
Chem., 2013, 288, 26764-26774.6. J. D. McCarter and S. G. Withers, J. Biol. Chem., 1996, 271, 6889-6894.7. R. Zhang, C. Li, L. K. Williams, B. P. Rempel, G. D. Brayer and S. G. Withers,
Biochemistry, 2009, 48, 10752-10764.8. B. W. Skelton, R. V. Stick, K. A. Stubbs, A. G. Watts and A. H. White, Aust. J. Chem. ,
2004, 57, 345-353.9. J. D. McCarter and S. G. Withers, J. Am. Chem. Soc., 1996, 118, 241-242.10. K. Igarashi, T. Honma and J. Irisawa, Carbohydr. Res., 1970, 13, 49-55.11. E. L. Myers, C. P. Butts and V. K. Aggarwal, Chem. Commun., 2006, 4434-4436.12. N. Chakraborty and M. d’Alarcao, Bioorg. Med. Chem., 2005, 13, 6732-6741.13. W. Bröder and H. Kunz, Bioorg. Med. Chem., 1997, 5, 1-19.14. K. Syson, C. E. Stevenson, A. M. Rashid, G. Saalbach, M. Tang, A. Tuukkanen, D. I.
Svergun, S. G. Withers, D. M. Lawson and S. Bornemann, Biochemistry, 2014, 53, 2494-2504.
15. A. Jha and N. Jain, Tetrahedron Lett., 2013, 54, 4738-4741.16. S. Dedola, D. L. Hughes and R. A. Field, Acta Crystallogr., Sect. C: Cryst. Struct.
Commun., 2010, 66, 124-127.17. J. D. McCarter and S. G. Withers, J. Am. Chem. Soc., 1996, 118, 241-242.
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