[(S)-2-((1aR,3aR,3bS,5aS,6R,8aS,8bS,10R,10aR)-10-Methoxy-3a,5a-dimethyl-hexadecahydro-cyclopenta[a]cyclopropa[2,3]cyclopenta[1,2-f]naphthalen-6-yl)-propylidene]-triphenyl-λ
5-phosphane 、 (RS)-2,2,4-trimethyl-1,3-dioxolan-4-acetaldehyd 以
四氢呋喃 为溶剂,
生成
(22Z/E)-(25RS)-25,26-(isopropylidendioxy)-6β-methoxy-3α,5-cyclo-5α-cholest-22-en