Synthesis of cyclopropanes by the reaction of olefins with dialkylzinc and methylene iodide

Abstract

A novel synthetic route to cyclopropanes by the reaction of olefins with dialkylzinc and methylene iodide is described. The essential feature of the reaction is similar to that of the Simmons-Smith reaction which involves the treatment of olefins with methylene iodide and zinc-copper couple. However, the novel route gives cyclopropanes more easily and is particularly suitable for the conversion of cationically polymerizable olefins such as vinyl ethers into the corresponding cyclopropanes. Olefins of this class, when the Simmons-Smith reaction is employed, sometimes give lower yields of cyclopropanes due to polymerization.