Acetoxy-Substituted Cyclopropane Dicarbonyls as Stable Donor–Acceptor–Acceptor Cyclopropanes

A study of cyclopropanations of oxy-substituted ethenes with ethyl α-aroyl-α-diazoacetates is described. The reaction of ethyl α-aroyl-α-diazoacetates with trimethylsilyl vinyl ether or ethyl vinyl ether gave dihydrofuran products, but when vinyl acetate was used the products were stable cyclopropanes, ethyl 2-acetoxy-1-aroylcyclopropanecarboxylates, which were isolated in 16–87% yield depending on the nature and position of the aryl-ring substituent.