Asymmetric Transformation of (RS)-2-Phenylglycine via Formation of Salt with (1S)-10-Camphorsulfonic Acid

Article abstract of DOI:10.1246/bcsj.64.191

An asymmetric transformation of (RS)-2-phenylglycine <(RS)-Phg> was carried out via formation of a salt with (1S)-10-camphorsulfonic acid <(S)-CS> in acetic acid, propanoic acid, or butanoic acid by heating at 100 deg C without using any catalysts such as aldehydes.The rate of epimerization of a more soluble salt of (S)-Phg with (S)-CS was estimated to be the lowest in acetic acid and highest in butanoic acid.The asymmetric transformation in propanoic acid, however, was achieved successfully to give the salt of (R)-Phg with (S)-CS with 100percent optical purity in 82percent yield.Optically pure (R)-Phg was obtained from the salt in 80percent yield based on the (RS)-Phg used as the starting material.