A Practical Method for Optical Resolution of 1,1′-Binaphthyl-2,2′-dicarboxylic Acid via 1-Phenylethylamides

Abstract

Both enantiomers of 1,1′-binaphthyl-2,2′-dicarboxylic acid (100% ee’s by HPLC) were conveniently obtained in high yields (ca. 80% of the theory) via fractional crystallization of the (S)-1-phenylethylamide diastereomers of the racemic acid followed by treatment with thionyl chloride and then alkaline hydrolysis.