(1aS,4aS,8aS)-8,8-Dimethyl-2,4a,5,6,7,8-hexahydro-1aH-1-oxa-cyclopropa[d]naphthalene-3-carboxylic acid ethyl ester 在
三氟化硼乙醚 作用下,
以
二氯甲烷 为溶剂,
以87%的产率得到(2aS,5aS,8aR)-1,1-Dimethyl-2a,3,5a,6,7,8-hexahydro-2-oxa-cyclobuta[d]indene-4-carboxylic acid ethyl ester