Acetic acid (3S,5S,7R,10S,13R,17R)-3-acetoxy-17-(3-chlorocarbonyl-1-methyl-propyl)-10,13-dimethyl-12-oxo-hexadecahydro-cyclopenta[a]phenanthren-7-yl ester 、
三氟乙酸酐 在
吡啶 作用下,
以
二氯甲烷 为溶剂,
反应 2.0h,
以67%的产率得到Acetic acid (3S,5S,7R,10S,13R,17R)-3-acetoxy-10,13-dimethyl-12-oxo-17-(5,5,5-trifluoro-1-methyl-4-oxo-pentyl)-hexadecahydro-cyclopenta[a]phenanthren-7-yl ester