tert-butyl (7R,8R,9R,13S,14S,17S)-3-acetoxy-17-tert-butoxy-13-methyl-7,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]phenanthrene-7-carboxylate 在
三氟化硼乙醚 作用下,
以
甲苯 为溶剂,
反应 5.0h,
以81%的产率得到(-)-(7S,8R,9R,13S,14S,17S)-3,17-dihydroxy-13-methyl-7,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]phenanthrene-7-carboxylic asid