1,1-二溴-3-甲基丁-1-烯 、
(20S)-6,6-ethylenedioxy-2α,3α-isopropylidenedioxy-5α-pregnane-20-carbaldehyde 在
正丁基锂 作用下,
以67.8%的产率得到(2S)-6-methyl-2-((1R,3aS,3bS,5aS,6aS,9aR,10aR,10bS,12aS)-8,8,10a,12a-tetramethylhexadecahydrospiro[cyclopenta[7,8]phenanthro[2,3-d][1,3]dioxole-5,2'-[1,3]dioxolan]-1-yl)hept-4-yn-3-ol