Catalytic Enantiospecific [3+2] Annulation of Aminocyclopropanes with Ketones

Abstract

An almost familiar ring: The first enantiospecific [3+2] annulation of donor-acceptor aminocyclopropanes with ketones is reported (see scheme; Phth=phthaloyl). The reaction is catalysed by tin(IV) chloride (5 mol %) at -78 °C and gives aminotetrahydrofurans bearing a quaternary C5 atom in high yield, diastereoselectivity and enantiospecificity (see scheme).