13
C NMR spectrum (CDCl , δ, ppm): 12.36 q, 13.22 t, 14.28 q, 19.44 q, 21.63 q, 22.85 t, 24.29 t, 25.10 t, 27.78 t,
3
29.53 t, 30.70 q, 32.08 t, 33.49 t, 35.17 t, 35.38 s, 40.15 t, 42.17 d, 42.82 s, 43.51 s, 48.07 d, 51.86 d, 56.44 d, 56.71 d, 65.50
d, 73.27 s, 82.50 d, 85.13 s.
(22S)-6β-Methoxy-3α,5-cyclo-27-nor-5α-cholest-23-yn-22-ol (4). PMR spectrum (CDCl , δ, ppm, J/Hz): 0.42
3
(1H, m, H-3), 0.72 (3H, s, CH -18), 1.01 (3H, s, CH -19), 1.10 (3H, d, J = 7, CH -21), 1.13 (3H, t, J = 8, CH -26), 2.21 (2H,
3
3
3
3
q, J = 7, H-25), 2.76 (1H, H-6), 3.32 (3H, s, COCH ), 4.45 (1H, br.s, H-22).
3
(22R,23Z)-6β-Methoxy-3α,5-cyclo-27-nor-5α-cholest-23-en-22-ol (5). Acetylenic alcohol 3 (100 mg, 0.25 mmol),
Lindlar catalyst (16 mg), and quinoline (0.1 mL) were dissolved in EtOAc (16 mL). The resulting suspension was stirred
under H for 2.5 h until H absorption was complete. The catalyst was filtered off. The solution was evaporated. The solid
2
2
was chromatographed over a column of silica gel (petroleum ether:EtOAc eluent, 20:1) to afford 5 (90 mg, 90%). IR spectrum
–1
(film, ν, cm ): 3400 (OH). PMR spectrum (CDCl , δ, ppm, J/Hz): 0.41–0.44 (1H, m, H-3), 0.73 (3H, s, CH -18), 0.88 (3H,
3
3
t, J = 9, CH -26), 0.90 (6H, d, J = 6.5, CH -21), 1.01 (3H, s, CH -19), 2.76 (1H, m, H-6), 3.31 (3H, s, OCH ), 4.26 (1H, m,
3
3
3
3
H-22), 5.51 (2H, m, H-23, H-24).
13
C NMR spectrum (CDCl , δ, ppm): 11.94, 12.33, 13.22, 19.42, 21.59, 22.89, 24.31, 25.089, 28.00, 29.86, 30.70,
3
32.08, 33.47, 35.19, 35.35, 40.28, 41.06, 42.80, 43.50, 48.08, 52.68, 56.50, 56.71, 74.36, 82.52, 113.73, 141.33.
(22E,24S)-6β-Methoxy-3α,5-cyclo-24-ethyl-5α-cholest-22-en-26-oic Acid Ethyl Ester (6). A solution of 5
(100 mg, 0.26 mmol) in benzene (8 mL) was treated with triethylorthopropionate (0.8 mL, 4.08 mmol) and propionic acid
(0.02 mL, 0.26 mmol) and refluxed under Ar for 2 h. After the reaction was finished, the mixture was treated with saturated
Na CO , extracted with EtOAc, and washed with water. The organic layer was evaporated. The solid was chromatographed
2
3
–1
over a column of silica gel (petroleum ether:EtOAc eluent, 20:1) to afford 6 (85 mg, 69%). IR spectrum (film, ν, cm ): 1735
(C=O). PMR spectrum (CDCl , δ, ppm, J/Hz): 0.71 (3H, s, CH -18), 0.99 (3H, d, J = 6.4, CH -21), 1.01 (3H, s, CH -19), 1.11
3
3
3
3
(3H, d, J = 7, CH -27), 1.25 (3H, t, J = 7, CH -29), 2.76 (1H, m, H-6), 3.31 (3H, s, OCH ), 4.11 (2H, q, J = 7, OEt), 5.21–5.29
3
(2H, m, H-22, H-23).
13
3
3
C NMR spectrum (δ, ppm): 12.57, 13.20, 14.41, 16.64, 19.42, 20.77, 20.80, 21.61, 22.88, 24.28, 24.31, 25.10,
28.73, 30.60, 33.48, 35.17, 35.41, 36.85, 39.95, 39.99, 40.26, 40.29, 42.83, 43.51, 48.16, 55.99, 56.71, 60.25, 82.53, 124.01,
139.76, 176.54.
(22E,24S)-3β-Hydroxy-24-ethyl-5α-cholest-5,22-dien-26-oic Acid Ethyl Ester (7). A mixture of 6 (200 mg,
0.4 mmol), p-TsOH (23 mg, 0.13 mmol), water (0.3 mL), and dioxane (5 mL) was heated at 70°C for 3 h, treated with pyridine,
and evaporated. The solid was chromatographed over a column of silica gel (petroleum ether:EtOAc eluent, 10:1) to afford 7
–1
(126 mg, 66%). IR spectrum (film, ν, cm ): 3440 (OH), 1735 (C=O). PMR spectrum (CDCl , δ, ppm, J/Hz): 0.68 (3H, s,
3
CH -18), 0.99 (3H, d, J = 6.5, CH -27), 1.04 (3H, s, CH -19), 1.15 (3H, d, J = 7, CH -21), 3.52 (1H, m, H-3), 4.11 (2H, q,
3
3
3
3
J = 7, OEt), 5.22–5.31 (2H, m, H-22, H-23), 5.35 (1H, m, H-6).
13
C NMR spectrum (CDCl , δ, ppm): 12.17,14.39, 16.63, 19.51, 20.80, 21.18, 24.40, 24.37, 28.67, 31.75, 32.00,
3
36.63, 36.74, 36.82, 37.38, 39.77, 39.93, 39.99, 40.22, 42.39, 50.24, 55.82, 56.93, 60.29, 71.89, 121.79, 124.05, 124.17,
139.69, 140.88, 176.57.
(22E,24S)-3α,5-Cyclo-24-ethyl-5α-cholest-22-en-6-on-26-oic Acid Ethyl Ester (8). Compound 7 (220 mg,
0.468 mmol) dissolved in CH Cl (3 mL) was treated with triethylamine (0.15 mL), cooled to –5°C, treated with a solution of
2
2
MsCl (107 mg, 0.936 mmol) in CH Cl (2 mL), stirred at –5°C for 25 min, treated with MeOH (0.01 mL), worked up with
2
2
water and saturated Na CO solution, and extracted with CH Cl . The extract was evaporated. The resulting mesylate was
2
3
2
2
dissolved in acetone (50 mL), treated with KOAc (250 mg) and water (4 mL), refluxed for 3 d, oxidized with Jones reagent
(1 mL), treated with isopropanol, passed over a layer of silica gel, and evaporated. The solid was chromatographed over a
–1
column of silica gel (petroleum ether:EtOAc eluent, 20:1) to afford 8 (110 mg, 50%). IR spectrum (film, ν, cm ):
1735 (C=O), 1700 (C=O). PMR spectrum (CDCl , δ, ppm, J/Hz): 0.72 (3H, s, CH -18), 1.01 (6H, m, CH -19,27), 1.18 (3H,
3
3
3
d, J = 7, CH -21), 4.12 (2H, q, J = 7, OEt), 5.26–5.29 (2H, m, H-22,23).
3
(22E,24S)-24-Ethyl-5α-cholest-2,22-dien-6-on-26-oic Acid Ethyl Ester (9). Ketone 8 (100 mg, 0.21 mmol) in
DMF (1.3 mL) was treated with Py⋅HBr (95 mg, 0.6 mmol), refluxed for 1 h under Ar, worked up with water, and extracted
with CHCl . The extract was evaporated. The solid was chromatographed over a column of silica gel (petroleum ether:EtOAc
3
–1
eluent, 15:1) to afford 9 (70 mg, 70%). IR spectrum (film, ν, cm ): 1735 (C=O), 1700 (C=O). PMR spectrum (CDCl , δ, ppm,
3
J/Hz): 0.66 (3H, s, CH -18), 0.69 (3H, s, CH -19), 0.99 (3H, d, J = 6.4, CH -27), 1.10 (3H, d, J = 7, CH -21), 4.10 (2H, q,
3
3
3
3
J = 7, OEt), 5.25 (2H, m, H-22,23), 5.56 (1H, m, H-2), 5.66 (1H, m, H-3).
650