Preparative resolution of 2-methyl-4-hexynic acid for the synthesis of optically active m-phenylene PGI 2 derivatives and determination of their absolute configuration

Abstract

Racemic 2-methyl-4-hexynic acid, which is a starting material for the ω-side chain of the PGI 2 derivatives, Beraprost and Iloprost, was efficiently resolved on a preparative scale by diastereomeric salt formation using quinine and cinchonidine as resolving agents. Their absolute configuration was determined by X-ray analyses of Beraprost derivatives.