Vinyl anions. Part 9. Vinyl carbanions derived from acrylic esters and their β-phenyl derivatives

Abstract

Ethyl ββ-diphenylacrylate, ethyl cis- and trans-cinnamate, methyl and ethyl maleate, ethyl fumarate, and methyl acrylate were treated with a strong base at low temperatures to yield the derived vinyl carbanions. The vinyl carbanions were treated with various electrophiles to give the corresponding α-substituted derivatives. Ethyl cis- and trans-cinnamate gave mostly β-substituted products having trans-geometry. The products obtained from the maleic esters were the corresponding fumarate derivatives. Deuteriation of ethyl cis-cinnamate gave the α-deuteriated ethyl cis-cinnamate. In the absence of an added electrophile dimers and trimers were isolated in the case of ethyl cis- and trans-cinnamate. Solvent, base, and temperature effects were also studied.