Isopropylidene glycerol hydrogen phthalate as a resolving agent: a study of its diastereomeric salts with (S)- and (R)-1-phenylethylamine

An insight into the mechanism of the highly efficient resolution of 1-phenylethylamine with enantiomerically pure isopropylideneglycerol hydrogen phthalate is provided by comparison of physicochemical and X-ray crystallographic data of the two diastereomeric salts formed by the amine with the S acid. In the nearly identical structures of these salts, the different disposition of the isopropylidene glycerol moiety stands out drawing attention to the critical role played by the chiral part of the acid in the discrimination between the amine enantiomers. Copyright (C) 2000 Elsevier Science Ltd.