J.W. Morzycki, A. Wojtkielewicz / Carbohydrate Research 337 (2002) 1269–1274
1273
(20S)-6i-Methoxy-16i,17h-dihydroxy-3h,5h-cyclo-
bisnorcholanaldehyde 22,16-hemiacetal 22-O-{O-[3,4-di-
Hz), 3.86 (s, 3 H), 3.75 (t, 1 H, J 7.7), 3.69 (m, 1 H),
3.55 (dd, 1 H, J 11.8, 3.6 Hz), 3.31 (s, 3 H), 3.24 (dd, 1
H, J 11.6, 8.6 Hz), 2.76 (m, 1 H), 2.36 (m, 1 H), 1.75 (s,
3 H), 0.81–1.05 (m, 43 H), 0.50–0.65 (m, 19 H), 0.43
(dd, 1 H, J 7.9, 5.1 Hz). 13C NMR (50 MHz, CDCl3):
l 169.8 (C), 164.5 (C), 163.2 (C), 131.7 (CH), 128.3
(CH), 122.8 (C), 115.1 (C), 113.4 (CH). ESIMS (m/z):
1252.8 (M+Na+).
O-triethylsilyl-2-O-(4-methoxybenzoyl)-i-
D-xylopyra-
nosyl]-(13)-4-O-triethylsilyl-h- -arabinopyranosyl 1,2-
L
orthoacetate} (12). Compound 12 was obtained as an
amorphous solid; Rf 0.25 (23:2 benzene–EtOAc); [h]D21
−4.0° (c 0.5, CHCl3). IR (CHCl3): w 3566, 1723, 1606,
1458, 1255, 1099, 1010 cm−1 1H NMR (500 MHz,
.
CDCl3): l 8.01 (d, 2 H, J 8.9 Hz), 6.92 (d, 2 H, J 8.9
Hz), 5.34 (d, 1 H, J 3.9), 5.29 (d, 1 H, J 4.8), 5.01 (t, 1
H, J 7.7 Hz), 4.77 (d, 1 H, J 7.2 Hz), 4.15 (m, 2 H),
4.02 (m, 1 H), 3.97 (dd, 1 H, J 11.6, 4.4 Hz), 3.87 (s, 3
H), 3.82–3.86 (m, 2 H), 3.70–3.75 (m, 2 H), 3.63 (dd,
1 H, J 11.5, 3.4 Hz), 3.33 (s, 3 H), 3.23 (dd, 1 H, J 11.6,
8.9 Hz), 2.77 (m, 1 H), 2.32 (dd, 1 H, J 7.0, 5.0 Hz),
1.67 (s, 3 H), 1.05 (s, 3 H), 0.80–1.00 (m, 40 H),
0.50–0.67 (m, 20 H), 0.45 (dd, 1 H, J 8.0, 5.1 Hz). 13C
NMR (50 MHz, CDCl3): l 164.7 (C), 163.2 (C), 131.6
(CH), 128.3 (CH), 122.9 (C), 121.6 (C), 113.5 (CH),
103.9 (CH), 100.6 (CH), 97.4 (CH). ESIMS (m/z):
1182.6 (M+Na+).
Glycosylation of hemiacetal 9.—The coupling reac-
tion of 9 with the disaccharide donor (Sugar*ꢀ
OꢀC(ꢁNH)CCl3) was performed according to the
procedure described above. The products obtained (10,
11, and 12) were separated and purified by silica gel
column chromatography. Pure aldehyde 11 (yield 30%)
was eluted with EtOAc (5%)–hexane, further elution
with EtOAc (7.5%)–hexane yielded consecutively com-
pounds 10 (39%) and 12 (9%).
(20S)-6i-Methoxy-16i,17h-dihydroxy-3h,5h-cyclo-
bisnorcholanaldehyde 16-O-{O-[3,4-di-O-triethylsilyl-2-
O-(4-methoxybenzoyl)-i-
D
-xylopyranosyl]-(13)-2-O-
acetyl-4-O-triethylsilyl-h-
L
-arabinopyranoside} (11).
Compound 11 was obtained as a white foam; Rf 0.34
(23:2 benzene–EtOAc); [h]2D1 −13.3° (c 0.5, CHCl3). IR
(CHCl3): w 3517, 2735, 1725, 1607, 1255, 1097, 1033
Alkylation of the aldehyde 11.—A solution of
isoamyl magnesium bromide in anhyd ether was pre-
pared from magnesium (6 mg, 0.26 mmol) and isoamyl
bromide (0.032 mL, 0.26 mmol). The Grignard reagent
was added dropwise to a stirred solution of compound
11 (150 mg, 0.13 mmol) in anhyd ether (10 mL) under
argon at −70 °C. The reaction mixture was stirred 4 h
at gradually increasing temperature to 0 °C. The reac-
tion mixture was quenched with satd aq NH4Cl and the
product was extracted with ether. The extract was dried
over MgSO4 and solvent was evaporated in vacuo. The
products were separated by silica gel column chro-
matography. Elution with EtOAc (15%)–hexane
yielded ketone 13 (71 mg, 50%). Further elution with
EtOAc (25%)–hexane afforded 3a (31 mg, 20%) identi-
cal (Rf, optical rotation, NMR spectra) with the com-
pound 3a described above.
1
cm−1. H NMR (500 MHz, CDCl3): l 9.54 (d, 1 H, J
0.8 Hz), 8.00 (d, 2 H, J 8.9 Hz), 6.92 (d, 2 H, J 8.9 Hz),
4.92 (dd, 1 H, J 6.7, 5.3 Hz), 4.86 (m, 1 H), 4.67 (d, 1
H, J 5.2 Hz), 4.14 (d, 1 H, J 4.5 Hz), 4.11 (m, 1 H),
3.98 (m, 1 H), 3.87 (s, 3 H), 3.65–3.86 (m, 4 H), 3.31 (s,
3 H), 3.22 (dd, 1 H, J 11.5, 7.4 Hz), 3.12 (m, 1 H), 3.07
(s, 1 H), 2.74 (m, 1 H), 1.90 (s, 3 H), 0.85–1.11 (m, 36
H), 0.50–0.65 (m, 20 H), 0.41 (dd, 1 H, J 7.9, 5.1 Hz).
13C NMR (50 MHz, CDCl3): l 207.6 (CH), 168.9 (C),
164.6 (C), 163.3 (C), 131.8 (CH), 128.3 (CH), 122.7 (C),
113.4 (CH). ESIMS (m/z): 1182.7 (M+Na+).
(20S)-6i-Methoxy-16i,17h-dihydroxy-3h,5h-cyclo-
bisnorcholanaldehyde 22,16-hemiacetal 22-O-{O-[3,4-di-
O-triethylsilyl-2-O-(4-methoxybenzoyl)-i-
nosyl]-(13)-2-O-acetyl-4-O-triethylsilyl-h-
D
-xylopyra-
-arabino-
L
6i-Methoxy-3h,5h-cycloandrostan-16i-ol-17-one 16-
pyranoside} (10). Compound 10: mp 126–130 °C
(prisms from hexane–CH2Cl2); Rf 0.22 (23:2 benzene–
EtOAc); [h]2D1 −12.0° (c 0.5, CHCl3). IR (CHCl3): w
O-{O-[3,4-di-O-triethylsilyl-2-O-(4-methoxybenzoyl)-
i-D
-xylopyranosyl]-(13)-2-O-acetyl-4-O-triethylsilyl-
h-
L
-arabinopyranoside} (13). Compound 12 was ob-
3518, 1731, 1606, 1458, 1255, 1097, 1004 cm−1
.
1H
tained as an oil; Rf 0.25 (4:1 hexane–EtOAc); [h]D21
NMR (500 MHz, CDCl3): l 7.98 (d, 2 H, J 8.9 Hz),
6.90 (d, 2 H, J 8.9 Hz), 5.34 (d, 1 H, J 4.8 Hz), 4.99 (t,
1 H, J 7.5 Hz), 4.90 (m, 1 H), 4.63 (d, 1 H, J 7.0 Hz),
4.55 (d, 1 H, J 5.7 Hz), 4.00 (m, 1 H), 3.97 (m, 1 H),
3.87 (s, 3 H), 3.83 (m, 1 H), 3.65–3.75 (m, 3 H), 3.39
(dd, 1 H, J 11.8, 1.8 Hz), 3.33 (s, 3 H), 3.19 (dd, 1 H,
J 11.5, 8.9 Hz), 2.76 (m, 1 H), 2.41 (m, 1 H), 1.86 (s, 3
H), 1.04 (s, 3 H), 0.92–1.00 (m, 20 H), 0.82–0.87 (m, 14
H), 0.45–0.67 (m, 20 H). 13C NMR (50 MHz, CDCl3):
l 169.6 (C), 164.8 (C), 163.6 (C), 163.3 (C), 131.8 (CH),
128.2 (CH), 122.4 (C), 113.4 (CH), 105.2 (CH). ESIMS
(m/z): 1182.7 (M+Na+).
−0.1° (c 1.5, CHCl3). IR (CHCl3): w 1739, 1726, 1607,
1
1255, 1096 cm−1. H NMR (200 MHz, CDCl3): l 7.95
(d, 2 H, J 8.8 Hz), 6.89 (d, 2 H, J 8.8 Hz), 4.98 (m, 2
H), 4.78 (d, 1 H, J 6.5 Hz), 4.68 (d, 1 H, J 6.9 Hz), 3.95
(m, 2 H), 3.85 (s, 3 H), 3.68–3.84 (m, 4 H), 3.32 (s, 3
H), 2.78 (m, 1 H). 13C NMR (50 MHz, CDCl3): l 217.8
(C), 168.8 (C), 164.5 (C), 163.2 (C), 131.8 (CH), 128.3
(CH), 122.9 (C), 113.3 (CH), 101.7 (CH), 100.4 (CH),
81.9 (CH). ESIMS (m/z): 1123.7 (M+Na+).
Deprotection of the functional groups.—Compound 4
(29 mg, 0.024 mmol) was dissolved in the solution of
PdCl2 (1.6 mg) in MeCN (2 mL), acetone (1.6 mL) and