(1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR 13bR)-benzyl 9-(4-(methoxycarbonyl)phenyl)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysene-3a-carboxylate → (1S,3aS,5aR,5bR,7aS,9S,11aS,11bR,13aR,13bR)-1-isopropyl-9-(4-(methoxycarbonyl)phenyl)-5a,5b,8,8,11a-pentamethylicosahydro-1H-cyclopenta[a]chrysene-3a-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of palladium on carbon (67.4 mg, 0.063 mmol) and (1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-benzyl 9-(4-(methoxycarbonyl)phenyl)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysene-3a-carboxylate (140 mg, 0.211 mmol) in methanol (2 mL) was stirred at 20° C. under hydrogen at 1 atmosphere of pressure for 20 hours. The reaction mixture was filtered through a celite pad to remove Pd/C. The filtrates were concentrated under reduced pressure to provide the title compound as a white solid (100 mg, 82%). LCMS: m/e 577.33 (M+H)+, 3.22 min (method 10).

Provenance & Evidence