3040
J. M. Brunel et al. / Tetrahedron: Asymmetry 16 (2005) 3036–3041
expected 7a-benzoyloxycholesterylacetate 2a in 76%
yield. White solid; mp 74 ꢁC; 1H NMR (CDCl3,
300 MHz) d 8.01–7.42 (m, 5H), 5.73–5.21 (m, 2H),
4.68–4.57 (m, 1H), 2.38–0.66 (m, 44H); 13C NMR
(CDCl3, 75 MHz) d 170.73, 166.49, 147.35, 133.10,
131.41, 129.96, 128.74, 121.18, 73.57, 69.30, 56.42,
49.99, 43.88, 42.73, 39.83, 38.22, 37.82, 37.40, 36.60,
36.19, 28.38, 28.01, 24.46, 24.32, 23.20, 22.91, 21.71,
21.20, 19.13, 18.61, 11.88. MS m/z: 549.3 [M+1] for
C36H52O4.
1H), 2.49–0.63 (m, 46H); 13C NMR (CDCl3, 75 MHz)
d 170.80, 166.46, 147.34, 138.48, 133.11, 131.35,
129.98, 128.74, 121.18, 73.59, 69.27, 56.06, 51.59,
50.10, 43.89, 42.59, 40.94, 39.53, 38.22, 37.82, 36.91,
36.57, 32.23, 29.20, 27.87, 25.76, 24.52, 24.24, 21.72,
21.47, 21.19, 19.36, 18.61, 17.88, 17.68, 12.62, 12.08.
MS m/z: 575.3 [M+1] for C38H54O4.
4.8. Synthesis of 7a-benzoyloxy-5-androstene-3b,17b
diacetate 14
1
4.3. Synthesis of 7a-benzoyloxycholesteryl-3b benzoate
2b
88% yield; viscous oil; H NMR (CDCl3, 300 MHz) d
8.05–7.45 (m, 5H), 5.75–5.73 (m, 1H), 4.69–4.55 (m,
1H), 2.41–0.80 (m, 31H); 13C NMR (CDCl3, 75 MHz)
d 172.00, 171.09, 166.78, 147.85, 133.68, 131.38,
130.27, 129.23, 121.30, 83.15, 73.80, 68.92, 44.96,
44.55, 43.11, 38.57, 38.22, 37.13, 37.05, 36.83, 28.20,
28.04, 24.08, 22.08, 21.92, 21.05, 19.01, 12.23. MS m/z:
495.6 [M+1] for C36H38O6.
69% yield; white solid; mp 92 ꢁC; 1H NMR (CDCl3,
300 MHz) d 8.01–7.37 (m, 10H), 5.53 (m, 1H), 5.42 (m,
1H), 4.85 (m, 1H), 2.77–0.70 (m, 41H); 13C NMR
(CDCl3, 75 MHz) d 165.57, 165.10, 141.47, 132.17,
131.30, 129.84, 129.12, 124.02, 73.35, 73.01, 56.45,
55.91, 47.21, 39.90, 39.83, 37.98, 37.71, 37.36, 36.64,
28.58, 28.25, 28.10, 25.62, 24.25, 22.70, 21.90, 19.08,
11.92. MS m/z: 611.8 [M+1] for C41H54O4.
4.9. Synthesis of 7a-hydroxy DHEA 15
77% overall yield (two steps); white solid; 1H NMR
(CDCl3, 300 MHz) d 5.55 (m, 1H), 4.78 (m, 1H), 3.54
(m, 1H), 2.72–0.86 (m, 25H); 13C NMR (CDCl3,
4.4. Synthesis of 7a-benzoyloxycholesteryl-3b-tert-butyl-
dimethylsilyloxy 2c
75 MHz)
d 220.11, 141.00, 127.39, 74.69, 71.96,
66% yield; white solid; mp 71 ꢁC; 1H NMR (CDCl3,
300 MHz) d 8.08–7.44 (m, 5H), 5.71–5.21 (m, 1H),
3.54–3.47 (m, 1H), 2.35 to À0.05 (m, 57H); 13C NMR
(CDCl3, 75 MHz) d 166.98, 166.52, 149.21, 133.28,
131.60, 130.51, 130.02, 128.71, 119.81, 72.30, 69.81,
56.49, 50.11, 43.96, 42.75, 39.85, 37.84, 38.23, 36.67,
36.21, 32.20, 30.11, 28.38, 26.29, 26.09, 24.35, 23.23,
22.94, 21.10, 19.17, 18.53, 18.24, 11.87, À4.19, À4.35.
MS m/z: 621.4 [M+1] for C40H64O3Si.
50.13, 49.62, 48.95, 42.39, 39.40, 38.58, 32.12, 31.45,
21.90, 21.57, 19.04, 14.15. MS m/z: 305.4 [M+1] for
C19H28O3.
4.10. Synthesis of 7a-hydroxycholesteryl-3b ol 16
61% overall yield (two steps); white solid; 1H NMR
(CDCl3, 300 MHz) d 5.63–5.61 (m, 1H), 3.88–3.83 (m,
1H), 3.65–3.55 (m, 1H), 2.35–0.70 (m, 43H); 13C NMR
(CDCl3, 75 MHz) d 146.65, 124.25, 71.71, 65.75, 56.25,
49.81, 42.65, 42.54, 39.92, 39.70, 37.91, 37.79, 37.50,
36.51, 36.16, 31.75, 28.67, 28.40, 24.69, 24.11, 23.20,
22.96, 21.10, 19.13, 18.64, 12.03. MS m/z: 403.3 [M+1]
for C27H46O2.
4.5. Synthesis of 7a-benzoyloxycholesteryl-3b ol 2d
31% yield; viscous oil; 1H NMR (CDCl3, 300 MHz)
d 8.02–7.26 (m, 5H), 6.13–4.86 (m, 4H), 2.53–0.81
(m, 41H); 13C NMR (CDCl3, 75 MHz) d 165.34,
142.92, 134.77, 131.06, 130.92, 129.91, 129.76, 124.76,
78.48, 75.80, 57.28, 54.69, 51.94, 51.36, 46.74,
44.67, 43.87, 40.81, 40.74, 39.01, 37.37, 37.33, 37.03,
29.42, 29.26, 29.20, 25.09, 24.07, 23.81, 21.93,
19.91, 17.54, 13.14, 13.05. MS m/z: 507.4 [M+1] for
C34H50O3.
References
1. (a) Fukazana, T.; Hashimoto, T. Tetrahedron: Asymmetry
1995, 4, 2323–2327; (b) Gupta, A. K.; Jaszlauskas, R. J.
Tetrahedron: Asymmetry 1993, 4, 879–883; (c) Asami, M.;
Ishizaki, T.; Inoue, S. Tetrahedron: Asymmetry 1994, 5,
793–797.
4.6. Synthesis of 7a-benzoyloxy DHEA-acetate 10
2. (a) Walling, C.; Zavitsas, A. A. J. Am. Chem. Soc. 1963,
85, 2084–2090; (b) Kochi, J. K. J. Am. Chem. Soc. 1962,
84, 774–784; (c) Goering, H. L.; Mayer, U. J. Am. Chem.
Soc. 1964, 86, 3753–3756; (d) Bulman Page, P. C.;
McCarthy, T. J. In Comprehensive Organic Synthesis;
Trost, B. M., Fleming, I., Eds.; Pergamon Press: Oxford,
1991; Vol. 7, pp 83–117; (e) Muzart, J. Bull. Soc. Chim. Fr.
1986, 65–77; (f) Kochi, J. K. Science 1967, 155, 415–
424.
3. Stephenson, L. M.; Grdina, M. R.; Orfanopoulos, M. Acc.
Chem. Res. 1980, 13, 419–425.
4. (a) Umbreit, M. A.; Sharpless, K. B. J. Am. Chem. Soc.
1977, 99, 5526–5528; (b) Stevenson, L. M.; Speth, D. R. J.
Org. Chem. 1979, 44, 4683–4689; (c) Sharpless, K. B.;
Lauer, R. F. J. Am. Chem. Soc. 1972, 94, 7154–7155; (d)
1
95% yield; white solid; mp 100 ꢁC; H NMR (CDCl3,
300 MHz) d 8.01–7.42 (m, 5H), 5.65 (m, 1H), 5.42 (m,
1H), 4.57 (m, 1H), 2.20–0.86 (m, 26H); 13C NMR
(CDCl3, 75 MHz) d 220.11, 170.40, 166.80, 141.42,
132.17, 129.87, 129.12, 124.02, 74.80, 72.39, 49.59,
48.70, 46.54, 37.95, 37.71, 36.55, 35.77, 31.50, 27.70,
21.75, 21.58, 21.27, 19.04, 14.03. MS m/z: 451.1 [M+1]
for C28H446O5.
4.7. Synthesis of 7a-benzoyloxystigmasteryl-3b acetate 12
1
76% yield; viscous oil; H NMR (CDCl3, 300 MHz) d
8.20–7.48 (m, 5H), 5.75–5.25 (m, 2H), 4.55–4.75 (m,