D. Li, T.A. Spencer / Steroids 65 (2000) 529–535
533
2H), 7.46 (m, 4H), 5.42 (m, 1H), 4.96 (m, 1H), 4.87 (m,
2.13. Cholest-5-ene-3,7␣,24(S)-triol (7)
1H), 1.07 (s, 3H), 1.00 (d, J ϭ 6.9 Hz, 3H), 0.98 (d, J ϭ 6.6
Hz, 3H), 0.95 (d, J ϭ 6.6 Hz, 3H), 0.66 (s, 3H); 13C NMR
166.7, 166.3, 139.9, 133.0, 133.0, 131.1, 130.9, 129.8,
128.6, 128.5, 123.0, 80.0, 74.8, 56.9, 56.0, 50.3, 42.6, 40.0,
38.5, 37.3, 36.9, 36.0, 32.1, 31.9, 31.5, 28.4, 28.1, 27.8,
24.5, 21.3, 19.7, 19.2, 19.0, 17.6, 12.1 (lit. [28] 13C NMR
(25.2 MHz) 165.5, 139.4, 132.7, 130.8, 129.6, 128.3, 122.5,
79.6, 74.5, 56.6, 55.6, 50.0, 42.2, 39.7, 38.2, 37.0, 36.6,
35.6, 31.8, 31.8, 31.2, 31.1, 28.1, 27.9, 27.3, 24.3, 21.1,
19.3, 18.9, 18.7, 17.3, 11.8.
As in the preparation of 5 from 15, 17.5 mg (0.0280
mmol) of 17 was converted to crude 7, which was chro-
matographed (4:1 EtOAc:hexane) to give 11.4 mg (97%) of
colorless 7 that was homogeneous by TLC. Recrystalliza-
tion twice from acetone-hexane gave 7: m.p. 203–204°C;
1H NMR (CD3OD) ␦ 5.53 (d, J ϭ 5.4 Hz, 1H), 3.76 (m,
1H), 3.47 (m, 1H), 3.21 (m, 1H), 1.00 (s, 3H), 0.97 (d, J ϭ
6.6 Hz, 3H), 0.91 (d, J ϭ 6.0 Hz, 3H), 0.89 (d, J ϭ 6.0 Hz,
3H), 0.72 (s, 3H). 13C NMR (CD3OD) 146.8, 125.1, 78.3,
72.2, 66.0, 57.5, 50.8, 43.5, 43.4, 43.0, 40.8, 39.1, 38.6,
38.2, 37.6, 34.7, 33.8, 32.3, 31.8, 29.5, 25.2, 22.0, 19.7,
19.6, 18.8, 17.7, 12.3; EI-HRMS (Mϩ-H2O) Analysis Cal-
culated for C27H42O: 400.3341. Found: 400.3349.
2.11. 3,24(S)-Dihydroxycholest-5-en-7-one 3,24-
Dibenzoate (14)
According to a procedure by Ratcliffe and Rodehorst
[29], to a solution of 16.0 mg (0.0256 mmol) of 11 in 0.3
ml of pyridine and 10 ml of dry CH2Cl2 was added 0.3 g
of CrO3. The mixture was heated at reflux overnight
under N2, decanted and evaporated to give a black resi-
due, which was taken up in 50 ml of ether and filtered.
The filtrate was washed with 10 mL of 5% NaHCO3
solution and 10 ml of brine, dried, filtered, and evapo-
rated to give 38.0 mg of yellow oil which was chromato-
graphed (1:9 EtOAc:hexane) to afford 12.7 mg (78%) of
14: m.p. 143–147°C. Recrystallization from CH2Cl2-hex-
ane three times gave 14: m.p. 151.6 to 152.4°C; 1H NMR
8.05 (m, 4H), 7.56 (m, 2H), 7.45 (m, 4H), 5.75 (s, 1H),
4.96 (m, 2H), 1.27 (s, 3H), 1.00 (d, J ϭ 6.9 Hz, 3H), 0.98
(d, J ϭ 6.9 Hz, 3H), 0.95 (d, J ϭ 6.3 Hz, 3H), 0.67 (s,
3H); 13C NMR 202.2, 166.7, 166.0, 164.1, 133.3, 133.0,
131.1, 130.5, 129.9, 129.8, 128.6, 128.6, 127.1, 80.0,
73.1, 54.6, 50.2, 50.0, 45.7, 43.4, 38.9, 38.7, 38.1, 36.3,
35.9, 31.8, 31.4, 28.7, 27.8, 27.7, 26.5, 21.4, 19.2, 19.2,
17.6, 17.6, 12.2. Analysis Calculated for C41H52O5: C,
78.80; H, 8.39. Found: C, 78.56, H, 8.37.
2.14. 24(S),25-Epoxycholesteryl-3-acetate (18)
To a solution of 40.4 mg (0.101 mmol) of 4, prepared as
previously described [30], in 1.5 ml of dry pyridine was
added 0.7 ml of acetic anhydride. The resulting mixture was
stirred under N2 for 12 h, 10 ml of saturated NaHCO3
solution was added, and the mixture was extracted with 3 ϫ
10 ml of CH2Cl2. The combined organic layers were dried,
filtered, and evaporated to give 109.7 mg of residue, which
was chromatographed on aluminum oxide (active neutral,
gamma, Ϫ60 mesh, AlfaAesar; 1:19 EtOAc:hexane) to give
36.7 mg (82%) of 18. Recrystallization from CH2Cl2-hex-
ane afforded colorless 18: m.p. 113 to 115°C (lit. [31] m.p.
114.5–116.5°C); 1H NMR 5.38 (m, 1H), 4.60 (m, 1H), 2.68
(m, 1H), 2.03 (s, 3H), 1.30 (s, 3H), 1.27 (s, 3H), 1.02 (s,
3H), 0.94 (d, J ϭ 6.3 Hz, 3H), 0.70 (s, 3H); 13C NMR 170.7,
139.8, 122.8, 74.2, 65.1, 58.3, 56.9, 56.2, 50.2, 42.6, 39.9,
38.3, 37.2, 36.8, 35.9, 32.8, 32.0, 29.9, 28.4, 28.0, 25.9,
25.2, 24.5, 21.7, 21.2, 19.5, 18.9, 18.8, 12.1.
2.15. 24(S),25-Epoxycholest-5-en-3-ol-7-one, 3-Acetate
(19)
2.12. Cholest-5-ene-3,7␣,24(S)-triol 3,24-Dibenzoate
(17)
According to a procedure by Salvador et al. [32], to a
solution of the crude product (40.6 mg) containing 18,
prepared as described above from 28.5 mg (0.0713 mmol)
of 4, and 8.1 mg of CuI in 2 ml of dry CH3CN was added
0.2 ml (5.0–6.0 M solution in decane, 1.0–1.2 mmol) of
t-BuOOH. The resulting mixture was stirred at 50°C for
25 h under N2, 10 ml of 10% Na2SO3 was added, and the
mixture was extracted with 3 ϫ 10 ml of CH2Cl2. The
combined organic layers were washed with 10 ml of satu-
rated NaHCO3 solution, 10 ml of H2O, and 10 ml of brine,
dried, filtered, and evaporated to give 60.4 mg of yellow
residue that was crystallized twice from CH2Cl2-hexane to
give 22.3 mg (69% from 4) of 19: m.p. 175.5–177.5°C; 1H
NMR 5.70 (s, 1H), 4.72 (m, 1H), 2.69 (m, 1H), 2.05 (s, 3H),
1.31 (s, 3H), 1.27 (s, 3H), 1.21 (s, 3H), 0.95 (d, J ϭ 6.6 Hz,
3H), 0.69 (s, 3H); 13C NMR 202.2, 170.6, 164.2, 127.0,
72.5, 65.1, 54.8, 50.2, 50.0, 45.7, 43.4, 38.9, 38.6, 38.0,
As in the preparation of 15 from 12, except for a reaction
time of three rather than 5 h, 34.9 mg (0.0558 mmol) of 14
was converted to 34.6 mg of crude 17, which was chro-
matographed (3:17 EtOAc:hexane) to give 24.2 mg (69%)
1
of 17: m.p. 171–173°C; H NMR 8.05 (m, 4H), 7.56 (m,
2H), 7.45 (m, 4H), 5.67 (d, J ϭ 5.1 Hz, 1H), 4.95 (m, 2H),
3.86 (m, 1H), 1.06 (s, 3H), 1.00 (d, J ϭ 6.9 Hz, 3H), 0.97
(d, J ϭ 6.6 Hz, 3H), 0.95 (d, J ϭ 5.7 Hz, 3H), 0.67 (s, 3H);
13C NMR 166.6, 166.1, 145.4, 133.0, 132.9, 131.1, 130.8,
129.8, 129.7, 128.5, 125.1, 80.0, 74.2, 65.4, 55.6, 49.6, 42.4,
42.3, 39.3, 38.2, 37.7, 37.7, 37.0, 35.8, 31.8, 31.4, 28.4,
27.8, 27.6, 24.4, 20.9, 19.1, 19.0, 18.5, 17.5, 11.8. FAB-
HRMS (M-Hϩ) Analysis Calculated for C41H53O5:
625.3893. Found: 625.3894.