(E)-(R)-6-((3S,7R,10S,13R,14R,15S,17R)-3,15-Diacetoxy-7-hydroxy-4,4,10,13,14-pentamethyl-2,3,4,5,6,7,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-17-yl)-2-methyl-hept-2-enoic acid methyl ester 在
硫酸 作用下,
生成
(E)-(R)-2-Methyl-6-((10S,13R,14R,17R)-4,4,10,13,14-pentamethyl-3,15-dioxo-2,3,4,5,6,10,12,13,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-17-yl)-hept-2-enoic acid methyl ester