氰基甲酸甲酯 、
(1S,2R,5S,6R,7R,9R,13S,15S,19S)-5,7,9,19-tetramethyl-17,20-dioxatetracyclo[13.2.2.12,6.01,13]icosane-4,16-dione 在
六甲基磷酰三胺 、
lithium hexamethyldisilazane 作用下,
以
四氢呋喃 为溶剂,
以90%的产率得到methyl (2S,3S,4aS,5R,8S,9R,10R,12R,15aS)-3,8,10,12-tetramethyl-7,18-dioxohexadecahydro-5,9-epoxy-4a,2-(epoxymethano)benzo[13]annulene-6-carboxylate