1902
S. Jarosz et al. / Tetrahedron: Asymmetry 12 (2001) 1895–1905
Acetate: [h]D −6.95 (c=0.6); 1H NMR: l 6.00 (ddd, J1%,6
9.8, J1%,2% 17.2, J1%,2%a 10.2, H-1%), 5.37 (d, J6,7 9.6, H-7),
5.20 (dd, J2%,2%a 1.2, H-2%), 5.13 (dd, H-2%a), 4.71 (d, J1,2
1.1, H-1), 4.34 (dd, J7,8 0.8, J8,9 5.2, H-8), 4.10 (dd, J3,4
9.0, J4,5 9.9, H-4), 4.02,(m, H-10 and H-11), 3.91 (m,
H-11a), 3.73 (m, H-2, H-3 and H-9), 3.63 (dd, J5,6 1.6,
H-5), 3.41 (m, H-6), 3.27 (OCH3), 1.96 (CH3CO2), 1.41,
1.36, 1.36 and 1.32 [2×C(CH3)2]; 13C NMR: l 170.3
(CꢁO), 137.5 (C-1%), 118.0 (C-2%), 109.7 and 109.4 [2×
C(CH3)2], 98.7 (C-1), 80.5, 78.9, 77.0, 76.9, 76.4, 75.8,
74.2 and 70.8 (C-2,3,4,5,7,8,9,10), 74.9, 73.0 and 72.1
(3×CH2Ph), 66.4 (C-11), 54.7 (OCH3), 43.6 (C-6), 27.6,
26.9, 26.4 and 25.3 [2×C(CH3)2], 21.3 (CH3CO2).
77.5, 76.8, 75.0, 71.9 and 71.5 (C-2,3,4,5,7,8,9,10), 74.3,
72.2 and 71.9 (3×CH2Ph), 66.9 (C-11), 55.5 (OCH3),
44.7 (C-6), 27.2 (double), 26.4 and 25.6 [2×C(CH3)2],
21.3 (CH3CO2).
4.3.5. Methyl 2,3,4-tri-O-benzyl-8-O-tert-butyldiphenyl-
silyl-6-deoxy-6-vinyl-a-
D
-manno- -erythro-octoside 21.
D
This compound was characterized as diacetate 23-Ac,
after removal of the TBDPS block with a HF·py com-
plex followed by reaction of resulting diol with Ac2O/
py. 23-Ac: HRMS (LSIMS) m/z: 641.2727
[C36H42NaO9 (M+Na+) requires: 641.2727]. [h]D +5.5;
1H NMR: l 5.87 (dt, J1%,6 9.9 J1%,2% 17.1, J1%.2%a 9.9, H-1%),
5.45 (ddd, J6,7 8.5, J7,8 2.3, J7,8% 6.5, H-7), 5.14 (m,
H-2%), 4.69 (d, J1,2 1.54, H-1), 4.44 (dd, J8,8a 12.2, H-8),
4.09 (t, J3,4 9.5, J4,5 9.5, H-4), 4.02 (dd, H-8a), 3.79 (dd,
J2,3 3.0, H-3), 3.73 (dd, H-2), 3.61 (dd, J5,6 1.6, H-5),
3.26 (OCH3), 3.02 (m, H-6), 1.97 and 1.90 (2×CH3CO2);
13C NMR: l 170.7 and 170.0 (2×CꢁO), 135.9 (C-1%),
118.2 (C-2%), 98.6 (C-1), 80.4, 76.5, 75.1, 73.5 and 70.4
(C-2,3,4,5,7), 74.7, 72.7 and 71.9 (3×CH2Ph), 64.6 (C-
8), 54.8 (OCH3), 43.8 (C-6), 21.1 and 20.7 (2×CH3CO2).
This compound was converted into its p-nitrobenzoate
derivative by action of p-nitrobenzoyl chloride in pyri-
dine; mp 84–85°C (heptane–ether). 13C NMR: l 163.4
(CꢁO), 137.0 (C-1%), 118.4 (C-2%), 109.7 and 109.2 [2×
C(CH3)2], 98.8 (C-1), 80.4, 79.3, 77.0, 76.7, 76.5, 75.8,
73.7 and 72.0 (C-2,3,4,5,7,8,9,10), 74.7, 72.6 and 71.7
(3×CH2Ph), 67.0 (C-11), 54.7 (OCH3), 45.1 (C-6), 27.1
(double), 26.5 and 25.3 [2×C(CH3)2].
No crystal suitable for X-ray analysis could be
obtained.
4.3.6. Methyl 2,3,4-tri-O-benzyl-8-O-tert-butyldiphenyl-
silyl-6-deoxy-6-vinyl-a-
D
-manno- -erythro-octoside 22.
L
Likewise this compound was characterized as diacetate
24-Ac. HRMS (ESI) m/z: 641.2733 [C36H42NaO9 (M+
4.3.3. Methyl 2,3,4-tri-O-benzyl-6-deoxy-8,9:10,11-di-O-
1
Na+) requires: 641.2721]. [h]D −10.7; H NMR: l 5.91
isopropylidene-6-vinyl-a-
D
-manno-
D
-galacto- -glycero-
D
undecoside 18%‡. HRMS (ESI) m/z: 727.3509
[C41H52NaO10 (M+Na+) requires: 727.3453].
(dt, J1%,6 10.2, J1%,2% 10.2, J1%.2%a 17.3, H-1%), 5.31 (dd, J2%,2%a
1.9, H-2%), 5.25 (ddd, J6,7 10.3, J7,8 2.4, J7,8a 5.2, H-7),
5.13 (dd, H-2%a), 4.66 (d, J1,2 2.3, H-1), 4.50 (dd, J8,8a
12.3, H-8), 3.96 (dd, H-8a), 3.88 (m, H-3 and H-4), 3.79
(dd, J5,6 1.4, H-5), 3.74 (t, J2,3 2.2, H-2), 3.22 (OCH3),
3.02 (H-6), 2.06 and 2.03 (2×CH3CO2); 13C NMR: l
170.6 and 170.5 (2×CꢁO), 133.0 (C-1%), 121.3 (C-2%),
98.9 (C-1), 80.3, 75.4, 74.5, 70.1 and 69.5 (C-2,3,4,5,7),
74.8, 72.3 and 71.8 (3×CH2Ph), 64.0 (C-8), 54.9
(OCH3), 45.1 (C-6), 21.1 and 20.7 (2×CH3CO2).
1
Acetate: H NMR: l 6.01 (dt, J1%,6 10.2, J1%,2% 17.3, J1%,2%a
10.2, H-1%), 5.37 (dd, J6,7 10.2, J7,8 1.6, H-7), 5.19 (dd,
J1%,2%a 2.2, H-2%), 5.06 (dd, H-2%a), 4.75 (d, J1,2 1.9, H-1),
4.40 (dd, J8,9 6.4, H-8), 4.11 (dd, J10,11 6.2, J11,11a 8.5,
H-11), 3.98 (ddd, J10,11a 5.7, H-10), 3.90 (m, H-3, H-4,
H-5, H-11a), 3.86 (dd, J2,3 2.0, H-2), 3.69 (dd, J9,10 8.5,
H-9), 3.38 (OCH3), 3.15 (t, H-6), 2.02 (CH3CO2), 1.46,
1.41, 1.36 and 1.24 [2×C(CH3)2]; 13C NMR: l 169.9
(CꢁO), 135.1 (C-1%), 119.8 (C-2%), 110.3 and 109.6 [2×
C(CH3)2], 98.9 (C-1), 80.0, 78.8, 78.0, 77.5, 75.8, 74.4,
71.1 and 70.7 (C-2,3,4,5,7,8,9,10), 74.4, 72.2 and 71.9
(3×CH2Ph), 67.8 (C-11), 55.3 (OCH3), 46.9 (C-6), 28.0,
26.9, 26.5 and 25.3 [2×C(CH3)2], 21.2 (CH3CO2).
For the CD assignment of the configuration at the C(7)
center of the diol 24, see Fig. 6.
4.4. Assignment of the configurations of 18, 21 and 22
4.4.1. Degradation of 18: methyl 2,3,4-tri-O-benzyl-6-
deoxy-6-vinyl-a-
D
-manno- -erythro-octoside 19. To a
D
4.3.4. Methyl 2,3,4-tri-O-benzyl-6-deoxy-8,9:10,11-di-O-
solution alcohol 18 (520 mg, 0.8 mmol) in DMF (25
mL) sodium hydride (60% dispersion in mineral oil, 100
mg) was added and the mixture was stirred for 30 min
at rt under an argon atmosphere. Allyl bromide (0.15
mL, 1.7 mmol) was added, the mixture was stirred for
another 2 h at rt, excess of hydride was decomposed by
careful addition of water (2 mL) and the mixture was
partitioned between water:ether. The organic phase was
separated, dried, concentrated and the product was
purified by column chromatography (hexane:ethyl ace-
tate, 6:1).
isopropylidene-6-vinyl-a-
D
-manno-D-talo-D-glycero-
undecoside 18%%. HRMS (LSIMS) m/z: 727.3443
[C41H52NaO10 (M+Na+) requires: 727.3458].
1
Acetate: H NMR: l 5.94 (dt, J1%,6 10.2, J1%,2% 17.4, J1%,2%a
10.2, H-1%), 5.49 (dd, J6,7 9.3, J7,8 3.5, H-7), 5.31 (dd,
J2%,2%a 2.0, H-2%), 5.06 (dd, H-2%a), 4.64 (d, J1,2 2.0, H-1),
4.15 (dd, J8,9 6.3, H-8), 4.05 and 3.89 (2×m, H-
3,4,5,9,10,11,11a), 3.73 (dd, J2,3 2.1, H-2), 3.30 (OCH3),
3.10 (m, H-6), 2.10 (CH3CO2), 1.35, 1.33, 1.28 and 1.27
[2×C(CH3)2]; 13C NMR: l 134.2 (C-1%), 120.5 (C-2%),
109.6 and 109.0 [2×C(CH3)2], 99.1 (C-1), 80.7, 80.2,
The product was dissolved in THF/water (2:1, v/v, 25
mL) to which conc. H2SO4 (0.5 mL) was added, the
mixture was heated under reflux for 16 h, cooled to rt
and neutralized by addition of solid sodium bicarbon-
ate. Sodium periodate (0.8 g) was added, the mixture
‡ The assignment of the configuration in 18% and 18%% is tentative; for
the more abundant isomer 18%% we proposed the alternative (to 18)
erythro structure, while for 18% the threo one with the same configu-
ration at the C(6) as in major isomer 18.