The synthesis of enantiomerically pure, symmetrically substituted cyclopropane phosphonic acids - a constrained analog of the GABA antagonist phaclophen

Article abstract of DOI:10.1016/S0040-4039(96)02518-X

The stereocontrolled conjugate addition of anions derived from chiral α-chlorophosphonamides to α,β-unsaturated esters leads to the corresponding 3-chloro ester adducts which undergo intramolecular expulsion of the chlorine atom to give the corresponding cyclopropanes.