乙酸酐 、 (1S,3bR,5aS,10aS,12aS)-1-Hydroxy-10a,12a-dimethyl-2,3,3a,3b,4,5,5a,6,10,10a,10b,11,12,12a-tetradecahydro-1H-7-oxa-dicyclopenta[a,h]phenanthren-9-one 在
吡啶 作用下,
以90%的产率得到Acetic acid (1S,3bR,5aS,10aS,12aS)-10a,12a-dimethyl-9-oxo-2,3,3a,3b,4,5,5a,6,8,9,10,10a,10b,11,12,12a-hexadecahydro-1H-7-oxa-dicyclopenta[a,h]phenanthren-1-yl ester