重氮甲烷 、
(1R,3aS,5aR,5bR,7aR,8S,9R,11aS,11bR,12R,13aR,13bR)-9,12-Diacetoxy-1-isopropenyl-5a,5b,8,11a-tetramethyl-icosahydro-cyclopenta[a]chrysene-3a,8-dicarboxylic acid 3a-methyl ester 以
甲醇 、
乙醚 为溶剂,
生成 (1R,3aS,5aR,5bR,7aR,8S,9R,11aS,11bR,12R,13aR,13bR)-9,12-Diacetoxy-1-isopropenyl-5a,5b,8,11a-tetramethyl-icosahydro-cyclopenta[a]chrysene-3a,8-dicarboxylic acid dimethyl ester