[(3S,5S,8R,9S,10S,13S,14S,17R)-10,13-dimethyl-17-[(2S)-6-methyl-3-oxoheptan-2-yl]-16-oxo-1,2,3,4,5,6,7,8,9,11,12,14,15,17-tetradecahydrocyclopenta[a]phenanthren-3-yl] acetate 、
1,2-乙二硫醇 在
三氟化硼乙醚 作用下,
以
二氯甲烷 为溶剂,
以99%的产率得到[(3S,5S,8R,9S,10S,13S,14S,17R)-10,13-dimethyl-17-[(2S)-6-methyl-3-oxoheptan-2-yl]spiro[1,2,3,4,5,6,7,8,9,11,12,14,15,17-tetradecahydrocyclopenta[a]phenanthrene-16,2'-1,3-dithiolane]-3-yl] acetate