Reaction Steps
To a stirred solution of (1R,3aS,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bR)-N-((1S,3R)-2,2-dimethyl-3-(morpholine-4-carbonyl)cyclobutyl)-9-hydroxy-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)icosahydro-1H-cyclopenta[a]chrysene-3a-carboxamide (Example 8, 0.250 g, 0.385 mmol) 2,2-Dimethylsuccinic anhydride (0.26 ml, 2.31 mmol) and DMAP (0.094 g, 0.77 mmol) in pyridine (10 ml) were added at room temperature then the reaction mixture was refluxed for about 16 hours. After completion of the reaction (monitored by TLC) the reaction mixture was diluted with EtOAc, the organic layer was washed with water, 1N HCl, water, brine and dried with Na2SO4, the solvent was evaporated and purified by silica gel column (100-200, elution 35% EtOAc in hexane) to afford the title compound as a off white solid. Wt: 0.140 g: Yield: 46.8%; 1H NMR. (300 MHz, CDCl3): δ 5.95 (d, 1H), 4.73 (s, 1H), 4.58 (s, 1H), 4.52-4.43 (m, 1H), 4.19-4.09 (m, 1H), 3.82-3.40 (m, 8H), 3.17-3.04 (m, 1H), 2.92-1.82 (m, 1H), 2.71-2.29 (m, 6H), 2.00-1.91 (m, 3H), 1.80-1.09 (m, 28H), 1.00-0.77 (m, 21H); Mass: [M+1]+ 779 (100%), [M+Na]+ 801 (15%); IR (KBr, cm−1): 3419, 2952, 2867, 1757, 1733, 1729, 1638, 1631, 1460, 1452, 1376, 1243, 1180, 1117, 1067, 978, 879, 775; M.R: 248.7° C.-252.6° C.; HPLC: 87.7%
