8-[(1S,3aS,7aS)-1-tert-butoxy-7a-methyl-2,3,3a,6,7,7a-hexahydro-1H-inden-5-yl]-1,4-dioxaspiro[4,5]dec-7-ene 、
6,6-二甲基-4,8-二氧杂螺[2.5]辛-1-烯 以
苯 为溶剂,
反应 12.0h,
以31%的产率得到(13S,14S,17S)-17-tert-butoxy-13-methylspiro(1'',3''-dioxolane[2'',3]-2,3,4,5,6,7,8,11,23,13,14,15,16,17-tetradecahydro-1H-(6',6'dimethyl-4',8'-dioxaspiro)[6',3]cyclopropa[6,7]cyclopenta[a]phenanthrene)