Reaction of α-Vinylallenylphosphonates with Diazoalkanes

Abstract

Diazomethane reacts with 3-methyl-1-vinyl-1,2-butadienylphosphonates following the scheme of [3 + 2]-cycloaddition at the 1,2-double bond of the allenic fragment. The reaction with diphenyldiazomethane involves the vinyl fragment and yields substituted diphenylcyclopropane.