G. V. M. Sharma et al. / Tetrahedron 58 -2002) 3801±3812
3811
First eluted was: 30-t-butyldiphenylsilyloxy-60-methoxy-2,2-
dimethyl--30R,3aR,5S,60S,60R,6aR)-spiro [perhydrofuro[2,
3-d][1,3]dioxole-6,20--30H,60H-pyran)]-5-ylmethanol ?34,
?5H, m, Ph), 5.88±5.70 ?2H, m, H-7,8), 5.60 ?1H, d,
J1,24.0 Hz, H-1), 5.52 ?1H, d, J6,72.5 Hz, H-6), 4.89
?1H, s, H-9), 4.40 ?1H, d, J1,24.0 Hz, H-2), 4.22±4.09
?2H, m, H-4,50), 3.92±3.80 ?1H, m, H-5), 3.21 ?3H, s,
OCH3), 2.12 ?3H, s, COCH3), 1.24, 1.20 ?6H, 2s, 6H,
CH3), 1.02 ?9H, s, CH3), 13C NMR ?50 MHz, CDCl3):
169.7, 135.6 ?3C), 135.4, 129.3 ?2C), 128.0, 127.8 ?2C),
127.4 ?3C), 111.8, 105.7, 94.7, 87.8, 79.8, 78.5, 70.9,
64.2, 56.0, 29.6, 26.8 ?4C), 26.3, 26.0, 20.9, 19.1;
FABMS: 591 ?M1123).
27
0.20 g, 33%), [a]D 219.8 ?c 1.0, CHCl3); dH
?200 MHz, CDCl3) 7.70±7.55 ?5H, m, Ph), 7.35±7.22
?5H, m, Ph), 5.82 ?1H, dd, J7,87.2 Hz, H-8), 5.66 ?1H,
dd, J7,87.2 Hz, H-7), 5.60 ?1H, d, J1,23.8 Hz, H-1), 5.29
?1H, br s, H-9), 4.49 ?1H, d, J1,23.8 Hz, H-2), 4.20 ?1H, br
s, H-6), 4.12±3.82 ?3H, m, H-4,5,50), 3.18 ?3H, s, OCH3),
1.30, 1.23, 1.20, 1.0 ?15H, 4s, CH3), m/z: ?FABMS), 549
?M1123), 469, 437; HRMS found: 526.2383. C29H38O7Si
requires 526.2386.
4.1.23. 5-t-Butyldiphenylsilyloxymethyl-40,50-dihydroxy-
60-methoxy-2,2-dimethyl-+30R,3aS,40R,5S,50R,60S,60S,
6aR)spiro[perhydrofuro[2,3-d][1,3]dioxole-6,20-+30H,
40H,50H,60H-pyran)]-3-yl acetate +38). To a stirred solu-
tion of 36 ?0.15 g, 0.26mmol) in acetone±water ?5 mL, 4:1)
were added sequentially NMO ?31 mg, 0.26mmol) and
OsO4 ?2 drops) at room temperature. After completion of
reaction ?1 week, monitored by TLC), the reaction mixture
was worked up as described for 15 and puri®ed by column
chromatography ?Si-gel, 60±120 mesh, 30% EtOAc±
hexane) to afford 5-t-butyldiphenylsilyloxymethyl-40,50-
dihydroxy-60-methoxy-2,2-dimethyl--30R,3aS,40R,5S,50R,
60S,60S,6aR)-spiro[perhydrofuro[2,3-d][1,3]dioxole-6,20-
-30H,40H,50H,60H-pyran)]-3-yl acetate ?38, 0.095 g, 60%)
as a syrup. Analysis found: C 61.56; H 6.82. C31H42O10Si
Second eluted was: 30-t-butyldiphenylsilyloxy-60-methoxy-
2,2-dimethyl--30R,3aR,5S,60R,60R,6aR)-spiro[perhydro-
furo[2,3-d][1,3]dioxole-6,20--30H,60H-pyran)]-5-ylmetha-
nol ?35, 0.21 g, 35%) as a syrup, Analysis found: C 65.97; H
27
7.03. C29H38O7Si requires C 66.13; H 7.27%; [a]D 10.42
?c 0.6, CHCl3); dH ?200 MHz, CDCl3) 7.80±7.67 ?5H, m,
Ph), 7.45±7.30 ?5H, m, Ph), 5.99 ?1H, dd, J7,87.8 Hz, H-8),
5.82 ?1H, dd, J7,87.8 Hz, J6,74.6Hz, H-7), 5.70 ?1H, d,
J1,24.2 Hz, H-1), 4.89 ?1H, br s, H-9), 4.53 ?1H, d,
J1,24.2 Hz, H-2), 4.20 ?1H, d, J6,74.6Hz, H-6), 4.16±
3.90 ?3H, m, H-4,5,50), 3.29 ?3H, s, OCH3), 1.28, 1.24,
1.21, 1.05 ?15H, 4s, CH3); m/z: ?FABMS), 549 ?M1123),
469, 437.
27
requires C 61.77; H 7.02%; [a]D 118.5 ?c 1.3, CHCl3);
4.1.21. 5-t-Butyldiphenylsilyloxymethyl-60-methoxy-2,2-
dimethyl-+30R,3aR,5S,60R,60S,6aR)spiro[perhydrofuro-
dH ?200 MHz, CDCl3) 7.80±7.65 ?5H, m, Ph), 7.46±7.30
?5H, m, Ph), 5.60 ?1H, d, J1,23.8 Hz, H-1), 5.20 ?1H, d,
J6,74.7 Hz, H-6), 4.95 ?1H, d, J1,23.8 Hz, H-2), 4.90 ?1H,
d, J8,97.2 Hz, H-9), 4.40 ?1H, t, J4.4 Hz, H-4), 4.05±
3.95 ?2H, m, H-7,8), 3.90±3.80 ?1H, m, H-50), 3.80±3.68
?1H, m, H-5), 3.50 ?3H, s, OCH3), 2.15 ?3H, s, COCH3),
1.41, 1.25, 1.02 ?15H, 3s, CH3); FABMS: 625 ?M1123).
[2,3-d][1,3]dioxole-6,20-+30H,60H-pyran)]-3-yl
acetate
+36). A solution of 34 ?0.2 g, 0.38 mmol) and Et3N
?0.13 mL, 0.95 mmol) in CH2Cl2 ?5 mL) was treated with
Ac2O ?0.06mL, 0.57 mmol) in presence of catalytic DMAP
at 08C and worked up as described for 7 afforded 5-t-butyl-
diphenylsilyloxymethyl-60-methoxy-2,2-dimethyl--30R,3aR,
5S,60R,60S,6aR)-spiro[perhydrofuro[2,3-d][1,3]dioxole-
6,20--30H,60H-pyran)]-3-yl acetate ?36, 0.15 g, 70%) as a
syrup. Analysis found: C 65.32; H 6.87. C31H40O8Si requires
4.1.24. 5-t-Butyldiphenylsilyloxymethyl-40,50-dihydroxy-
60-methoxy-2,2-dimethyl-+30R,3aR,40R,5S,50R,60R,60S,
6aR)-spiro[perhydrofuro[2,3-d][1,3]dioxole-6,20-+30H,
40H,50H,60H-pyran)]-3-yl acetate +39). To a stirred solu-
tion of 37 ?0.1 g, 0.17 mmol) in acetone±water ?5 mL, 4:1)
were added sequentially NMO ?21 mg, 0.17 mmol) and
OsO4 ?2 drops) at room temperature. After completion of
reaction ?1 week, monitered by TLC), the reaction mixture
was worked up as described for 15 and puri®ed by column
chromatography ?Si-gel, 60±120 mesh, 30% EtOAc±
hexane) to afford 5-t-butyldiphenylsilyloxymethyl-40,50-
dihydroxy-60-methoxy-2,2-dimethyl--30R,3aR,40R,5S,50R,
60R,60S,6aR)-spiro[perhydrofuro[2,3-d]-[1,3]dioxole-6,20-
-30H,40H,50H,60H-pyran)]-3-yl acetate ?39, 0.035 g, 39%)
as a syrup. Analysis found: C 61.52; H 6.88. C31H42O10Si
27
C 65.47; H 7.09%; [a]D 135.5 ?c 0.25, CHCl3); dH
?200 MHz, CDCl3) 7.75±7.60 ?5H, m, Ph), 7.42±7.30
?5H, m, Ph), 5.93±5.88 ?2H, m, H-7,8), 5.80 ?1H, d,
J1,24.1 Hz, H-1), 5.58 ?1H, d, J6,72.2 Hz, H-6), 5.42
?1H, br s, H-9), 4.53 ?1H, d, J1,24.1 Hz, H-2), 4.12±4.0
?2H, m, H-4,50), 3.94±3.87 ?1H, m, H-5), 3.21 ?3H, s,
OCH3), 2.12 ?3H, s, COCH3), 1.40, 1.39, 1.22, 1.02 ?15H,
4s, CH3); dC ?50 MHz, CDCl3) 169.5, 135.7 ?2C), 135.6
?2C), 133.5, 129.4 ?2C), 128.9 ?2C), 127.5 ?3C), 113.7,
105.5, 95.5, 84.9, 82.5, 81.4, 69.1, 63.0, 54.1, 29.3, 26.8
?4C), 26.7 ?2C), 20.9, 19.1; m/z: ?FABMS), 591 ?M1123).
27
4.1.22. 5-t-Butyldiphenylsilyloxymethyl-60-methoxy-2,2-
dimethyl-+30R,3aR,5S,60R,60R,6aR)-spiro[perhydrofuro-
requires C 61.77; H 7.02%; [a]D 215.7 ?c 2.2, CHCl3);
dH ?200 MHz, CDCl3) 7.76±7.65 ?5H, m, Ph), 7.42±7.30
?5H, m, Ph), 5.60 ?1H, d, J1,24.0 Hz, H-1), 5.39 ?1H, br d,
J6,79.6Hz, H-6), 4.53 ?1H, br s, H-9), 4.46?1H, d, J1,2
4.0 Hz, H-2), 4.31±4.10 ?2H, m, H-7,8), 4.0±3.85 ?3H, m,
H-4,5,50), 3.35 ?3H, s, OCH3), 2.15 ?3H, s, COCH3), 1.25,
1.20, 1.05 ?15H, 3s, CH3), FABMS: 625 ?M1123).
[2,3-d][1,3]dioxole-6,20-+30H,60H-pyran)]-3-yl
acetate
+37). A solution of 35 ?0.2 g, 0.38 mmol) and Et3N
?0.13 mL, 0.95 mmol) in CH2Cl2 ?5 mL) was treated with
Ac2O ?0.06mL, 0.57 mmol) in presence of catalytic DMAP
at 08C and worked up as described for 8 to afford 5-t-butyl-
diphenylsilyloxymethyl-60-methoxy-2,2-dimethyl--30R,3aR,
5S,60R,60R,6aR)-spiro-[perhydrofuro[2,3-d][1,3]dioxole-
6,20--30H,60H-pyran)]-3-yl acetate ?37, 0.11 g, 55%) as a
syrup. Analysis found: C 65.37; H 6.91. C31H40O8Si requires
4.1.25. 5-t-Butyldiphenylsilyloxymethyl-60-methoxy-2,2-
dimethyl-30,40-di+methylcarbonyloxy)-+30R,3aR,40R,5S,
50R,60S,60S,6aR)-spiro[perhydrofuro[2,3-d][1,3]dioxole-
6,20-+30H,40H,50H,60H-pyran)]-5-yl acetate +5). A solution
of the diol 38 ?30 mg, 0.05 mmol) in CH2Cl2 ?5 mL) was
27
C 65.47; H 7.09; [a]D 218.5 ?c 1.5, CHCl3); dH
?200 MHz, CDCl3) 7.76±7.60 ?5H, m, Ph), 7.45±7.30