甲氧羰基亚甲基三苯基正膦 、
5,5;20,20-bis(ethylenedioxy)-4,5-secopregnan-4-al 以
二氯甲烷 为溶剂,
以50%的产率得到methyl (E)-6-[(3S,3aS,5aS,6R,9aS,9bS)-3a,6-dimethyl-3-(2-methyl-1,3-dioxolan-2-yl)spiro[1,2,3,4,5,5a,8,9,9a,9b-decahydrocyclopenta[a]naphthalene-7,2'-1,3-dioxolane]-6-yl]hex-2-enoate