[1-[(8S,9S,10R,13S,14S)-10,13-dimethyl-3-oxo-7,8,9,11,12,14,15,16-octahydro-6H-cyclopenta[a]phenanthren-17-ylidene]-2-oxoethyl] 2-methylpropanoate 在
1,8-二氮杂双环[5.4.0]十一碳-7-烯 作用下,
以
乙酸乙酯 为溶剂,
反应 6.0h,
以90%的产率得到Isobutyric acid 2-((8S,9S,10R,13S,14S)-10,13-dimethyl-3-oxo-6,7,8,9,10,11,12,13,14,15-decahydro-3H-cyclopenta[a]phenanthren-17-yl)-2-oxo-ethyl ester