A general strategy for the amino acid homologation via Blaise reaction and subsequent reduction is presented. This strategy involves the preparation of protected α-amino nitriles from the corresponding amino acids, followed by the zinc-mediated condensation of tert-butyl bromoacetate, to give the imidazolidones after iminozincate cyclization. Reduction gave the saturated imidazolidinones with cis or
cyclopropanation of Michael acceptors. Ephedrine-derived azetidinium ylides allowed the formation of substituted cyclopropanes in good yields and at a high level of stereoselectivity. The determination of the relative stereochemistries in the produced cyclopropanes gave some insight into the reaction mechanism.