ENANTIOMER SEPARATION BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH (R,R)-TARTARIC ACID MONO-AMIDE DERIVATIVES AS BIFUNCTIONAL CHIRAL SELECTORS

Three mono-amide derivatives of (R,R)-tartaric acid derived from (R)-1 -(alpha-naphthyl)ethylamine (I), (S)-valine-(S)-1(alpha-naphthyl)ethyl amide (II) and (R)-valine-(R)-1-(alpha-naphthyl)ethylamide (III) were prepared and their chromatographic properties as chiral selectors were examined by HPLC. The enantiomeric separation of derivatives of racem ic amino acids, amines, carboxylic acids and alcohols was achieved wit h these chiral selectors ionically bonded to 3-aminopropyl silica gel using organic mobile phases. In this separation the chiral amine or am ino acid amide moiety may play an important role in chiral recognition . On the other hand, the direct separation of racemic amino acids and hydroxy acids was accomplished with these chiral selectors in the form of copper(II) complexes coated on the reversed-phase materials using aqueous mobile phases containing copper(II) ions. In this separation t he (R,R)-tartaric acid moiety may contribute to the chiral recognition . These results clearly show that these (R,R)-tartaric acid mono-amide derivatives can act as bifunctional chiral selectors, and they are pr omising for the enantiomeric separation of a wide range of racemic com pounds by HPLC.