Stereospecific synthesis of highly functionalized benzo[3.1.0]bicycloalkanes via multistep cascade reactions

Abstract

A facile approach for the synthesis of benzo[3.1.0]bicycloalkanes via alkylation/cyclopropanation cascade reactions of benzyl bromide with triphenylphosphonium bromide has been developed. By elaborate designing of starting materials, this multistep cyclization proceeded smoothly with a wide range of substrates, providing the benzo[3.1.0]bicycloalkanes in 52–90% yields with exclusive diastereoselectivity.