Efficient Syntheses of Multisubstituted Methylenecyclopropanes via Novel Ultrasonicated Reactions of 1,1-Dihaloolefins and Metals.

Abstract

Ultrasonicated reactions of 1,1-dihaloolefins with lithium, magnesiumor sodium in the presence of alkenes rapidly afford multisubstitutedmethylenecyclopropanes. E.g., dibromomethylenecyclohexane reactedwith lithium and cyclohexene in THF in the water bath of an ultrasoniccleaner to give carbene addn. product I in 85% yield. [on SciFinder(R)]