The synthesis of enantiomerically pure, symmetrically substituted cyclopropane phosphonic acids — A constrained analog of the GABA antagonist phaclophen
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.
The asymmetric synthesis of α-chloro α-alkyl and α-methyl α-alkyl phosphonic acids of high enantiomeric purity.
作者:Stephen Hanessian、Youssef L. Bennani、Daniel Delorme
DOI:10.1016/s0040-4039(00)97091-6
日期:1990.1
A method is described for the synthesis of α-chloro-α-alkyl- and α-methyl-α-alkylphosphonic acids in either enantiomeric form and in high optical purity, based on the asymmetric alkylation of α-substituted bicyclic phosphonamides derived from a C2 symmetrical diamine.