Reaction Steps
To a stirred solution of (1R,3aS,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bR)-9-((1S,3R)-3-(benzyloxycarbonyl)-2,2-dimethylcyclobutanecarbonyloxy)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)icosahydro-1H-cyclopenta[a]chrysene-3a-carboxylic acid (Example 18, 0.25 g) in dry DCM (10 ml) Et3N (5.77 ml) and Et3SiH (0.057 g) were added at about 0° C. then Pd(OAc)2 (0.005 g) was added under nitrogen conditions and the reaction mixture was stirred at reflux temperatures for over night. After completion of the reaction (monitored by TLC), the reaction mixture was diluted with DCM, and concentrated under reduced pressure, purified by column chromatography to afford the title compound (80 mg, 36.86% Yield). 1H NMR (300 MHz, CDCl3): δ 4.73 (1H, s), 4.54 (1H, s), 4.4-4.36 (1H, m), 3.0-2.90 (1H, m), 2.80-2.65 (2H, m), 2.6 (2H, m), 2.3-2.1 (3H, m), 2.0-1.88 (4H, m), 1.64 (5H, m), 1.61 (2H, m), 1.6-1.4 (4H, m), 1.39-1.3 (4H, m), 1.32 (6H, s), 1.3-1.02 (4H, m), 1.00 (3H, s),0.91 (3H, s), 0.89 (3H, s), 0.809 (3H, s), 0.790 (3H, s), 0.751 (3H, s); Mass: [M+Na]+ 633 (75%); 1R (KBr, cm−1): 3400, 2949, 1732, 1703, 1459, 1389, 1364, 1264, 1211, 1139, 1126, 1106, 1020, 942, 889. Melting Range: 308-310° C.
