Epoxidation of 6-Deoxyhex-5-enopyranosides
J . Org. Chem., Vol. 67, No. 11, 2002 3739
(dd, 1H, J ) 4.8, 9.7 Hz), 5.25 (dd, 1H, J ) 1.5 Hz), 5.22 (dd,
1H, J ) 4.8, 2.3 Hz), 4.07 (d, 1H, J ) 8.3 Hz), 3.43 (dd, 1H, J
) 8.3 Hz), 2.14, 2.13, 2.01 (each s, each 3H); 13C NMR (CDCl3)
δ 172.7, 170.2, 169.8 (each s), 102.1 (s), 99.2 (d), 73.2, 69.5,
68.0 (each d), 66.7 (t), 21.0, 20.9, 20.7 (each q); IR (CH2Cl2
solution) ν 3588, 3053, 2987, 1754, 1423, 1373, 1265, 1230,
1056, 738, 705 cm-1; CI-HRMS m/z found 322.1136, required
322.1138 [M + NH4]+.
affording the title compound as a clear syrup (0.17 g, 63%):
[R]20 +12.3° (c 1.46, CHCl3); 1H NMR (CDCl3, 270 MHz) δ
D
5.43 (d, 1H, J ) 1.8 Hz), 5.26 (apt t, 1H, J ) 8.4 Hz), 5.13
(dd, 1H, J ) 1.8 Hz), 4.89 (dd, 1H, J ) 1.8, 8.4 Hz), 4.18 (d,
1H, J ) 8.4 Hz), 3.39 (dd, 1H, J ) 1.8, 8.4 Hz), 2.06, 2.03,
1.99 (each s, each 3H), 0.82 (s, 9H), 0.16 (s, 6H); 13C NMR
(CDCl3) δ 170.3, 170.2, 169.7 (each s), 102.7 (s), 98.2 (d), 74.2,
73.7, 71.0 (each d), 69.7 (t), 25.4 (s), 17.7 (q), 0.43, 0.24 (each
q); IR (liquid film) ν 2960, 2860, 1748, 1473, 1369, 1227, 1130,
1042, 842, 685 cm-1; CI-HRMS m/z found 436.2004, required
436.2002 [M + NH4]+.
2,3,4-Tr i-O-b en zyl-1,6-a n h yd r o-â-L-id op yr a n os-5-u l-
ose (26). 13 (4.5 g, 0.01 mol), 1,1,1-trifluoroacetone (10 mL,
0.1 mol), Na2EDTA (50 mL of a 4.0 × 10-4 M aq solution),
oxone (30 g, 0.05 mol), and NaHCO3 (6.51 g, 0.07 mol) in MeCN
(70 mL) were reacted as described above for 12 h. Chroma-
tography (EtOAc/petroleum ether gradient, 1:4 to 1:1) gave the
2,3,4-Tr i-O-ben zyl-5-O-a cetyl-1,6-a n h yd r o-â-L-id op yr a -
n os-5-u lose (32). A catalytic quantity of DMAP (10 mg) was
added to a solution of 26 (0.1 g, 0.2 mmol) in acetic anhydride
(5 mL) and pyridine (5 mL). The mixture was stirred overnight.
Water and EtOAc were added and the layers separated. The
aq layer was further extracted with EtOAc. The combined
organic extracts were washed with aq NaHCO3 and water and
dried (MgSO4), and the solvent was removed under diminished
pressure. Chromatography (EtOAc/petroleum ether gradient,
1:8 to 1:4) gave 26 as a clear syrup (0.073 g, 67%): [R]20D +42.3°
title compound as a white solid (4.36 g, 95%): [R]20 +34.5° (c
D
1.0, CHCl3); mp 98-99 °C; 1H NMR (CDCl3, 270 MHz) δ 7.22-
7.34 (ms, 15H, aromatic), 5.26 (d, 1H, J ) 2.0 Hz), 4.61-4.94
(ms, 6H), 4.19 (d, 1H, J ) 8.0 Hz), 3.79 (apt t, 1H, J ) 8.0
Hz), 3.68 (dd, 1H, J ) 2.0, 8.0 Hz), 3.53 (dd, 1H, J ) 8.0, 2.0
Hz), 3.31 (dd, 1H, J ) 8.0, 2.0 Hz); 13C NMR δ 138.4, 138.2,
137.7 (each s, each aromatic C), 128.8-127.7 (18C, each d, each
aromatic CH), 103.5 (s), 98.4 (d), 82.6 (d), 82.0 (d), 75.6, 74.7,
73.0 (each t), 68.5 (t); IR (solution in CHCl3) ν 3356, 2323, 1453,
1344, 1208, 1067, 1003, 836, 754 cm-1; CI-HRMS m/z found
466.2290, required 466.2291 [M + NH4]+.
1
(c 1.0, CHCl3); H NMR (CDCl3, 270 MHz) δ 7.31-7.24 (ms,
15H), 5.35 (d, 1H, J ) 2.0 Hz), 4.89-4.62 (m, 6H), 4.35 (d,
1H, J ) 8.0 Hz), 4.31 (dd, 1H, J 2.0, J ) 8.0 Hz), 3.83 (apt t,
1H, J ) 8.0 Hz), 3.80 (dd, 1H, J ) 8.0, 2.0 Hz), 3.63 (dd, 1H,
J ) 8.0, 2.0 Hz), 2.00 (s, 3H); 13C NMR δ 168.0 (s), 138.3, 138.0,
137.7 (each s), 128.6-127.7 (18C, each d), 104.2 (s), 99.3, 82.5,
82.4, 80.4 (each d), 75.5, 74.9, 73.1 (each t), 68.1 (t), 21.6 (q);
2,3,4-Tr i-O-b e n zyl-1,6-a n h yd r o-L-gu lop yr a n os-5-u l-
ose (27). Reaction of 1,1,1-trifluoroacetone (2 mL, 20 mmol),
Na2EDTA (10 mL of a 4.0 × 10-4 M aq solution), 14 (0.899 g,
2 mmol), oxone (6 g, 10 mmol), and NaHCO3 (1.3 g, 14 mmol)
in MeCN (15 mL) for 15 h gave 27 as a clear syrup (0.432 g,
48%) after chromatography (EtOAc/petroleum ether, 1:4):
IR (liquid film) ν 2923, 1761, 1454, 1363, 1219, 1074, 737 cm-1
;
CI-HRMS m/z found 508.2346, required 508.2335 [M + NH4]+.
2,3,4-Tr i-O-b en zyl-5-O-m et h yl-1,6-a n h yd r o-â-L-id op y-
r a n os-5-u lose (33). Iodomethane (0.16 g, 1.6 mmol) was
added dropwise to a solution of 26 (0.35 g, 0.8 mmol) and
sodium hydride (62 mg, 1.6 mmol) in anhydrous DMF at 0 °C
under a N2 atmosphere. The reaction mixture was stirred for
15 h. Water and EtOAc were added and the layers separated.
The aq layer was further extracted with EtOAc. The organic
extracts were combined and dried (MgSO4), and the solvent
was removed under diminished pressure. Chromatography
(EtOAc/petroleum ether, 1:4) gave the title compound as a
[R]20 +14.2° (c 0.8, CHCl3); 1H NMR (CDCl3, 270 MHz) δ
D
7.32-7.27 (ms, 15H), 5.28 (d, 1H, J ) 2.0 Hz), 4.72 (m, 6H),
3.99 (d, 1H, J ) 9.0 Hz), 3.99 (dd, 1H, J ) 1.0, 9.0 Hz), 3.73
(dd, 1H, J ) 4.5, 9.0 Hz, H-3), 3.66 (dd, 1H, J ) 4.5, 2.0 Hz),
3.24 (dd, 1H, J ) 1.0, 9.0 Hz); 13C NMR (CDCl3) δ 138.5, 138.0,
137.8 (each s), 128.8-127.5 (18C, each d), 102.6 (s), 99.4 (d),
81.4 (d), 78.5 (d), 75.0 (d), 75.2, 73.1, 73.0 (each t), 66.9 (t);
IR (liquid film) ν 3421, 2929, 1454, 1364, 1260, 1112, 799,
697 cm-1; CI-HRMS m/z found 466.2230, required 466.2220
[M + NH4]+.
clear syrup (0.284 g, 79%): [R]20 +17.4° (c 0.26, CHCl3);
D
2-O-Ben zyl-3,4-d i-O-isop r op ylid en e-1,6-a n h yd r o-â-L-ta -
lop yr a n os-5-u lose (28) a n d 2-O-Ben zyl-3,4-d i-O-isop r o-
pyliden e-1,6-an h ydr o-r-D-galactopyr an os-5-u lose (29). Re-
action of 1,1,1-trifluoroacetone (1.63 mL, 16.3 mmol), Na2EDTA
(8.15 mL of a 4.0 × 10-4 M aq solution), 15 (0.50 g, 1.63 mmol),
oxone (4.9 g, 8.1 mmol), and NaHCO3 (1.06 g, 11.4 mmol) in
MeCN (11.4 mL) for 15 h gave an interconverting mixture of
the title compounds as a clear syrup (0.27 g, 48%) after
chromatography (EtOAc/petroleum ether, 1:5 to 1:1, gradient
elution); CI-HRMS m/z found 326.1606, required 326.1603
[M + NH4]+.
1H NMR (CDCl3, 500 MHz) δ 7.18-7.28 (ms, 15H), 5.18 (d,
1H, J ) 2.0 Hz), 4.83-4.56 (ms, 6H), 3.93 (d, 1H, J ) 8.0 Hz),
3.71 (apt t, 1H, J ) 8.0 Hz), 3.68 (dd, 1H, J ) 2.0, 8.0 Hz),
3.56 (dd, 1H, J ) 8.0, 2.0 Hz), 3.47 (dd, 1H, J ) 8.0, 2.0 Hz),
3.42 (s, 3H, OMe); 13C NMR (CDCl3) δ 138.5, 137.9 (each s),
129.6-127.6 (18C, each d), 106.3 (s), 98.3, 82.7, 82.3, 81.3 (each
d), 75.5, 74.4, 73.0, 63.5 (each t), 50.6 (q); IR (liquid film)
ν 1651, 1453, 1365, 1260, 1098 cm-1; CI-HRMS m/z found
480.2387, required 480.2386 [M + NH4]+.
2,3,4-Tr i-O-ben zyl-5-tr iflu or om eth a n esu lfon yl-1,6-a n -
h yd r o-â-L-id op yr a n os-5-u lose (34). Trifluoromethanesulfon-
ic anhydride (0.054 mL, 0.32 mmol) was added dropwise to a
stirred solution of 26 (0.072 g, 0.16 mmol) and 2,6-lutidine
(0.075 mL, 0.64 mmol) in CH2Cl2 (2 mL) at -40 °C under N2.
The reaction mixture was allowed to attain room temperature
and stirred for a further15 h. The mixture was then diluted
with CH2Cl2, washed successively with 5% CuSO4 and water
(2×), and dried (Na2SO4) and the solvent removed under
diminished pressure. Chromatography (EtOAc/petroleum ether,
1:6, as eluant) gave recovered 26 (22 mg) followed by the title
Selected NMR data for 28: 1H NMR (CDCl3, 270 MHz) δ
7.26-7.36 (ms, 5H), 5.38 (s, 1H), 3.36 (d, J ) 7.9 Hz), 1.53,
1.33 (each s, each 3H); 13C NMR (CDCl3) δ 137.1 (s), 127.9-
128.5 (3 d), 109.0 (s), 102.0 (s), 100.9 (d), 77.5, 76.6, 75.2 (each
d), 72.2, 66.3 (each t), 26.0, 24.2, 21.9 (each q).
Selected NMR data for 29: 1H NMR (CDCl3, 270 MHz) δ
7.26-7.36 (ms, 5H, aromatic H), 5.42 (d, 1H, J ) 2.6 Hz), 4.71,
4.61 (each d, each 1H, J ) 12.2 Hz) 3.47 (dd, 1H, J ) 4.6, 2.6
Hz), 1.47, 1.40 (each s, each 3H); 13C NMR (CDCl3) δ 137.4
(s), 127.9-128.5 (3 d), 111.7 (s), 101.1 (s), 100.1 (d), 78.7, 78.2,
77.5 (each d), 71.5, 69.1 (each t), 27.4, 26.2, 21.9 (each q).
2,3,4-Tr i-O-a cetyl-5-O-ter t-bu tyld im eth ylsilyl-1,6-L-a n -
h yd r oid op yr a n os-5-u lose (31). tert-Butyldimethylsilyl tri-
fluoromethanesulfonate (0.59 mL, 2.4 mmol) was added drop-
wise to a solution of 21 (0.196 g, 0.65 mmol) and 2,6-lutidine
(0.52 mL, 4.2 mmol) in anhydrous CH2Cl2 at -40 °C under a
N2 atmosphere. The reaction mixture was allowed to warm to
room temperature and stirred for a further 1.5 h. Water and
CH2Cl2 were then added, and the two phases were separated.
The organic phase was washed with 5% CuSO4 and water (2×)
and dried (Na2SO4) and the solvent removed under diminished
pressure. The residue was purified using column chromatog-
raphy (gradient elution, EtOAc/petroleum ether, 1:10 to 1:4),
compound as a clear syrup (45 mg, 48%): [R]20 +15.4° (c 1.0,
D
CHCl3); 1H NMR (CDCl3, 270 MHz) δ 7.25-7.32 (ms, 15H),
5.42 (d, 1H, J ) 2.0 Hz), 4.87-4.56 (m, 6H), 4.37 (d, 1H, J )
8.0 Hz), 4.08 (dd, 1H, J ) 2.0, 8.0 Hz), 3.94 (dd, 1H), 3.78 (apt
t, 1H, J ) 8.0 Hz), 3.63 (dd, 1H, J ) 2.0, 8.0 Hz); 13C NMR δ
137.8, 137.3, 137.0 (each s, each aromatic C), 128.7-127.8
(18C, each d, each aromatic CH), 111.0 (s), 100.1, 82.1, 82.0,
81.5 (each d), 75.6, 75.3, 73.3 (each t), 67.5 (t); IR (liquid film)
2922, 1601, 1420, 1215, 1091, 799 cm-1; CI-HRMS m/z found
598.1728, required 598.1722 [M + NH4]+.
2,3,4-Tr i-O-b en zyl-5-O-ter t-b u t yld im et h ylsilyl-1,6-a n -
h yd r o-â-L-id op yr a n os-5-u lose (35). tert-Butyldimethylsilyl
trifluoromethanesulfonate (0.23 mL, 1 mmol) was added
dropwise to a stirred solution of 26 (0.3 g, 0.67 mmol) and 2,6-