Enantiomerically selective cyclopropanation

Abstract

A method of forming a cyclopropane having enhanced chirality said method comprising reacting together (1), a symmetrical 1,2-dioxine of the formula (1), wherein X and Y are the same and are groups in which a carbon atom is bonded to the dioxine backbone; and a phosphorus ylide or a phosphorus ylide precursor; in the presence of a cobalt catalyst containing a chiral ligand.