6490
P. Ghosh et al. / Tetrahedron 68 (2012) 6485e6491
51% yield; Rf (30% ethyl acetate/petroleum ether) 0.45; 1H NMR
(300 MHz, CDCl3): 0.68 (s, 1H), 0.81 (d, J¼6.9 Hz, 3H), 0.86 (d,
J¼6.9 Hz, 6H), 0.92 (d, J¼6.6 Hz, 3H), 1.18 (s, 3H), 3.51e3.61 (m, 1H),
4.15 (s, 1H), 5.68 (s, 1H); 13C NMR (75 MHz, CDCl3): 11.9, 12.0, 18.8,
19.0, 19.8, 20.5, 21.1, 23.1, 24.3, 25.4, 26.0, 28.2, 29.1, 31.8, 32.1, 33.9,
36.0, 36.1, 36.9, 39.7, 42.3, 45.8, 50.2, 56.0, 56.9, 72.5, 77.3, 128.8,
142.8; IR (Nujol, cmꢁ1): 3392, 1172, 1069, 977. Elemental analyses:
found: C, 80.89; H,11.66. C29H50O2 requires C, 80.86; H, 11.71%.
ethyl acetate/petroleum ether) 0.55; 1H NMR (300 MHz, CDCl3):
0.74 (s, 3H), 0.92 (d, J¼6.3 Hz, 6H), 0.97 (d, J¼6.3 Hz, 3H), 1.31 (s,
3H), 2.21 (s, 1H), 4.45 (s, 1H), 5.01e5.06 (m, 1H), 5.79 (s, 1H), 7.49 (t,
J¼7.5 Hz, 2H), 7.61 (t, J¼6.6 Hz, 1H), 8.11 (d, J¼7.5 Hz, 2H); 13C NMR
(75 MHz, CDCl3): 11.3, 18.1, 20.0, 20.5, 21.3, 22.0, 22.3, 23.3, 23.7,
27.5, 27.7, 31.2, 31.6, 35.2, 35.6, 35.7, 36.5, 39.0, 39.1, 41.8, 49.7, 55.5,
56.3, 75.1, 75.5, 127.8 (2), 129.1 (3), 129.7, 132.5, 140.9, 165.1; IR
(Nujol, cmꢁ1): 3533 (sharp), 1694, 1682, 1282, 1127, 1068, 1026, 967,
920, 845, 709. DART-MS (ESIþ), m/z: 491 (7%), 490 (37), 489 (100),
368 (3), 367 (10). Elemental analyses: found: C, 80.65; H, 9.84.
C34H50O3 requires C, 80.57; H, 9.95%.
4.4.6. 4b,7a-Dihydroxy b-sitosterol (3b,4b,7a-trihydroxy-5-b-sitos-
tene, 4b). White solid, mp 192e193 ꢀC; 22e72% yield; Rf (70% ethyl
acetate/petroleum ether) 0.55; 1H NMR (300 MHz, DMSO-d6): 0.63
(s, 3H), 0.79 (d, J¼6.3 Hz, 3H), 0.83 (d, J¼6.0 Hz, 6H), 0.91 (d,
J¼6.3 Hz, 3H), 1.07 (s, 3H), 3.26e3.38 (m, 1H), 3.64 (t, J¼3.0 Hz, 1H),
3.89 (d, J¼3 Hz, 1H), 5.58 (d, J¼4.8 Hz, 1H); 13C NMR (75 MHz,
DMSO-d6): 11.9, 12.2, 12.3, 19.1, 19.4, 19.6, 20.2, 23.0, 24.2, 25.4, 25.8,
28.4, 29.1, 33.8, 36.0, 36.9, 37.4, 37.9, 41.9, 42.3, 45.6, 49.4, 55.8, 63.8,
72.1, 77.1, 129.2, 145.7; IR (Nujol, cmꢁ1): 3392, 1165, 1078, 967. El-
emental analyses: found: C, 77.88; H, 11.32. C29H50O3 requires C,
77.96; H, 11.29%.
4.4.11. 3b-Benzoxy-6a-hydroxy-4-cholestene (7b). Needle shaped
white crystals (CHCl3/MeOH), mp 142e144 ꢀC, 34% yield; Rf (12%
ethyl acetate/petroleum ether) 0.55; 1H NMR (300 MHz, CDCl3):
0.66 (s, 3H), 0.86 (d, J¼6.6 Hz, 6H), 0.91 (d, J¼6.3 Hz, 3H), 1.20 (s,
3H), 3.75 (t, J¼6 Hz, 1H), 5.67 (s, 1H), 5.93 (d, J¼3 Hz, 1H), 7.44 (t,
J¼7.5, 2H), 7.55 (t, J¼7.2 Hz, 1H), 8.04 (d, J¼8.1 Hz, 2H); 13C NMR
(75 MHz, CDCl3): 11.8, 18.7, 20.7, 22.6, 22.8, 23.8, 24.2, 26.0, 28.0,
28.2, 31.7, 32.1, 35.8, 36.0, 36.2, 36.8, 39.5, 39.6, 42.3, 50.2, 56.1, 56.8,
72.0, 80.0, 128.4, 128.4, 129.6, 129.6, 130.5, 132.0, 133.0, 138.9, 166.8;
IR (Nujol, cmꢁ1): 3442, 3392, 1686, 1674, 1273, 1170, 1110, 977, 899,
759, 711. DART-MS (ESIþ), m/z: 491 (4%), 490 (36), 489 (100), 386
(26), 385 (89), 368 (24), 367 (83). Elemental analyses: found: C,
80.48; H, 9.86. C34H50O3 requires C, 80.57; H, 9.95%.
4.4.7. 3b,4b,7a-Triacetoxy-5-cholestene (4aa). Colourless cubic
crystals (CHCl3/MeOH), mp 170e171 ꢀC; 94% yield from 4a; Rf (5%
ethyl acetate/petroleum ether) 0.75; 1H NMR (300 MHz, CDCl3):
0.66 (s, 3H), 0.86 (d, J¼6.3 Hz, 6H), 0.92 (d, J¼6.6 Hz, 3H), 1.14 (s,
3H), 2.01 (s, 3H), 2.04 (s, 3H), 2.06 (s, 3H), 4.77e4.82 (m,1H), 5.06 (t,
J¼4.5 Hz, 1H), 5.52 (s, 1H), 5.93 (d, J¼6.0 Hz, 1H); 13C NMR (75 MHz,
CDCl3): 11.4 (CH3), 18.8 (CH3), 20.2 (CH2), 21.2 (CH3), 21.3 (CH3), 21.6
(CH3), 22.3 (CH2), 22.6 (CH3), 22.8 (CH3), 23.9 (CH2), 24.1 (CH2), 28.0
(CH), 28.1 (CH2), 35.7 (CH), 35.8 (CH), 36.2 (CH2), 36.3 (CH2), 37.0
(C), 38.9 (CH2), 39.5 (CH2), 42.2 (CH), 43.5 (CH), 49.0 (CH), 55.9 (CH),
67.6 (CH), 72.2 (CH), 75.0 (CH), 128.4 (CH), 143.9 (C), 169.7 (C), 170.2
(C), 170.4 (C); IR (Nujol, cmꢁ1): 1734, 1365, 1246, 1044, 1012, 976,
941, 889. DART-MS (ESIþ), m/z: 485 (6%), 426 (29), 425 (100), 384
(5), 383 (17), 366 (5), 365 (16). Elemental analyses: found: C, 79.69;
H, 10.62. C33H52O3 requires C, 79.77; H, 10.56%.
4.4.12. 4
b
-Hydroxy
diosgenin
(3b,4b-dihydroxy-5-spirostene,
12). White solid, mp 171e173 ꢀC, 30e58% yield; Rf (30% ethyl ace-
tate/petroleum ether) 0.45; 1H NMR (300 MHz, CDCl3): 0.79 (d,
J¼3.0 Hz, 3H), 0.80 (s, 3H), 0.97 (d, J¼6.8 Hz, 3H), 1.21 (s, 3H), 2.32
(s,1H), 2.43 (d, J¼6 Hz,1H), 3.37 (t, J¼10.8 Hz,1H), 3.46 (d, J¼3.0 Hz,
1H), 3.48e3.55 (m, 1H), 4.13 (d, J¼3 Hz, 1H), 4.40 (dd, J¼15.0 and
7.5 Hz, 1H), 5.66 (d, J¼2.7 Hz, 1H); 13C NMR (75 MHz, CDCl3): 14.5
(CH3), 16.3 (CH3), 17.1 (CH3), 20.3 (CH2), 21.0 (CH3), 25.3 (CH2), 28.8
(CH2), 30.3 (CH), 31.4 (CH2), 31.8 (CH2), 32.2 (CH), 36.2 (C), 36.9
(CH2), 39.7 (CH2), 40.3 (C), 41.6 (CH), 50.1 (CH), 56.6 (CH2), 62.0
(CH), 66.9 (CH2), 72.4 (CH), 77.2 (CH), 80.8 (CH), 109.3 (C), 128.3
(CH), 142.9 (C); IR (Nujol, cmꢁ1): 3392, 1169, 1047, 976. FABMS, m/z:
432 (37%), 431 (90), 430 (39), 429 (77), 414 (49), 413 (100), 412 (27),
411 (28), 395 (25). Elemental analyses: found: C, 75.21; H, 9.79.
C27H42O4 requires C, 75.29; H, 9.84%.
4.4.8. 3b-Acetoxy-4b-hydroxy-5-cholestene (6a). White solid, mp
175e176 ꢀC, 35% yield; Rf (15% ethyl acetate/petroleum ether) 0.45; 1H
NMR (300 MHz, CDCl3): 0.68 (s, 3H), 0.86 (d, J¼6.6 Hz, 6H), 0.91 (d,
J¼6.6 Hz, 3H), 1.22 (s, 3H), 2.11 (s, 3H), 4.25 (s, 1H), 4.69e4.76 (m, 1H),
5.71 (s,1H); 13CNMR(75 MHz, CDCl3): 11.9 (CH3),18.7 (CH3), 20.5 (CH2),
21.1 (CH3), 21.4 (CH3), 21.7 (CH2), 22.6 (CH3), 22.8 (CH3), 23.8 (CH2), 24.2
(CH2), 28.0 (CH), 28.2 (CH2), 31.7 (CH), 32.1 (CH2), 35.8 (CH), 36.2 (CH2),
36.6 (C), 36.9 (CH2), 39.5 (CH2), 39.6 (CH2), 42.3 (C), 50.2 (CH), 56.1 (CH),
56.8 (CH), 75.5 (CH), 75.6 (CH),129.5 (CH),141.5 (C),170.2 (C); IR (Nujol,
cmꢁ1):3412,1737,1279,1046.DART-MS(ESIþ), m/z: 429 (11%), 428 (61).
427 (100%), 385 (16), 368 (18), 367 (58). Elemental analyses: found: C,
78.39; H, 10.79. C29H48O3 requires C, 78.31; H, 10.89%.
4.4.13. 4b,7a-Dihydroxy diosgenin (3b,4b,7a-trihydroxy-5-
spirostene, 13). White solid, mp 201e202 ꢀC, 17e69% yield; Rf
(70% ethyl acetate/petroleum ether) 0.50; 1H NMR (300 MHz,
CDCl3): 0.79 (d, J¼3.0 Hz, 3H), 0.80 (s, 3H), 0.98 (d, J¼6.9 Hz, 3H),
1.20 (s, 3H), 3.37 (t, J¼10.8 Hz, 1H), 3.45e3.49 (m, 1H), 3.52e3.64
(m, 1H), 3.94 (t, J¼4.5 Hz, 1H), 4.09e4.19 (m, 1H), 4.48 (dd, J¼15.0
and 7.5 Hz, 1H), 5.86 (d, J¼4.8 Hz, 1H); 13C NMR (75 MHz, CDCl3):
14.6 (CH3), 16.1 (CH3), 17.2 (CH3), 19.4 (CH3), 20.0 (CH2), 25.1 (CH2),
28.8 (CH2), 30.3 (CH), 31.4 (CH2), 31.9 (CH2), 36.6 (CH2), 37.2 (CH),
39.1 (CH2), 40.4 (C), 41.7 (CH), 42.5 (CH), 49.0 (CH), 62.0 (CH), 65.2
(CH), 66.9 (CH2), 72.1 (CH), 76.9 (CH), 80.8 (CH), 109.3 (C), 129.6
(CH), 146.9 (C); IR (Nujol, cmꢁ1): 3395, 1172, 1054, 978. Elemental
analyses: found: C, 72.49; H, 9.41. C27H42O5 requires C, 72.59; H,
9.48%.
4.4.9. 3b-Acetoxy-6a-hydroxy-4-cholestene (7a). White solid, mp
139e140 ꢀC, 32% yield; Rf (20% ethyl acetate/petroleum ether) 0.45;
1H NMR (300 MHz, CDCl3): 0.68 (s, 3H), 0.87 (d, J¼6.6 Hz, 6H), 0.91
(d, J¼6.6 Hz, 3H), 1.18 (s, 3H), 2.08 (s, 1H), 3.60e3.69 (m, 1H), 5.38
(d, J¼2.7 Hz, 1H), 5.85 (d, J¼3.0 Hz, 1H); 13C NMR (75 MHz, CDCl3):
11.8 (CH3), 18.7 (CH3), 20.4 (CH3), 20.6 (CH2), 21.6 (CH3), 22.6 (CH3),
22.8 (CH3), 23.8 (CH2), 24.2 (CH2), 25.8 (CH2), 28.0 (CH), 28.2 (CH2),
31.6 (CH), 32.1 (CH2), 35.8 (CH), 36.0 (C), 36.2 (CH2), 36.8 (CH2), 39.5
(CH2), 39.6 (CH2), 42.3 (C), 50.2 (CH), 56.1 (CH), 56.8 (CH), 71.7 (CH),
79.3 (CH), 128.8 (CH), 138.8 (C), 171.2 (C); IR (Nujol, cmꢁ1): 3398,
1738, 1260, 1237, 1074. DART-MS (ESIþ), m/z: 428 (14%), 427 (43),
385 (77), 368 (29). Elemental analyses: found: C, 78.38; H, 10.96.
C29H48O3 requires C, 78.31; H, 10.89%.
4.4.14. 19-Norergosta-1,3,5,7,9,14,22-heptaene (9). Pale yellow
needles, mp 125e126 ꢀC (Chloroform/methanol), 5.5e12% yield; Rf
(petroleum ether) 0.95; 1H NMR (300 MHz, CDCl3): 0.84 (d,
J¼4.2 Hz, 3H), 0.88 (d, J¼4.2 Hz, 3H), 0.95 (s, 3H), 0.98 (d, J¼5.1 Hz,
3H), 1.15 (d, J¼6.6 Hz, 3H), 1.52 (m, 1H), 1.76 (m, 1H), 1.90 (m, 1H),
1.61 and 2.33 (m, 2H), 2.33 (m, 1H), 2.21 and 2.36 (m, 2H), 3.14 and
3.29 (m, 2H), 5.24 (m, 1H), 5.30 (m, 1H), 6.12 (t, J¼3 Hz, 1H), 7.42 (m,
1H), 7.45 (m, 1H), 7.50 (m, 1H), 7.64 (m, 1H), 7.77 (d, J¼7.8 Hz, 1H),
8.01 (d, J¼9.0 Hz, 1H); 13C NMR (75 MHz, CDCl3): 15.4 (CH3), 17.7
4.4.10. 3
b-Benzoxy-4b-hydroxy-5-cholestene (6b). White feather
like crystals (CHCl3/MeOH), mp 202e204 ꢀC, 37% yield; Rf (10%