Preparative Scale Directed Resolution of Enantiomeric Carboxylic Acids and Lactones via Liquid Chromatography and Neighboring-Group Assisted Hydrolysis of Diastereomeric Amides

The separation of enantiomeric carboxylic acids (1) on a preparative scale (1 mol) can be accomplished by the following reaction sequence: transformation of (1) with optically active amines, e.g. (2), containing polar groups, into diastereomeric amides → separation of the amides by liquid chromatography on silica gel columns → mild acidic hydrolysis. Amines such as (3) without additional polar groups suffice for separation of lactones.