乙酸酐 、
(3aS,5bR,11aS,13R,13aS,13bS)-13-Hydroxy-5b,8,8,11a,13a-pentamethyl-octadecahydro-2-oxa-cyclopenta[a]chrysen-1-one 以
吡啶 为溶剂,
反应 12.0h,
以90%的产率得到Acetic acid (3aS,5bR,11aS,13R,13aS,13bS)-5b,8,8,11a,13a-pentamethyl-1-oxo-icosahydro-2-oxa-cyclopenta[a]chrysen-13-yl ester