Reaction Steps
A solution of (1R,3aS,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bR)-3a-((1S,3R)-3-(4-ethylpiperazine-1-carbonyl)-2,2-dimethylcyclobutylcarbamoyl)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)icosahydro-1H-cyclopenta[a]chrysen-9-yl acetate (Example 66, 0.760 g) in MeOH:THF (2:1) (45 ml) at 0° C., 2N NaOH (15 ml) were added and allowed to stir at room temperature for about 16 hours. After completion of the reaction (monitored by TLC), the volatiles were evaporated, the aqueous layer extracted with ethyl acetate and dried with Na2SO4. The solvent was evaporated and purified by silica gel column (100-200 mesh, elution 15% EtOAc in hexane) to afford the title compound as a white solid. Wt: 0.500 g: Yield: 69.9%; 1H NMR (300 MHz, CDCl3): δ 5.90 (d, J=8.1 Hz, 1H), 4.728 (s, 1H), 4.57 (s, 1H), 4.10 (m, 1H), 3.80-3.41 (m, 4H), 3.20-3.10 (m, 2H), 2.9 (m, 1H), 2.60-2.295 (m, 9H), 2.1 (m, 2H), 1.90 (m, 1H), 1.80-1.02 (m, 22H), 0.95, 0.92 (s, 6H), 0.83 (s, 3H), 0.80 (s, 3H). Mass: [M+H+]+ 679 (100%); IR (KBr, cm−1): 3445, 2946, 2867, 1634, 1459, 1463, 1376, 1270, 1242, 1126, 1043, 983, 883, 768, 656; M.R: 122.0° C.-155.1° C.; HPLC: 94.8%.
