PREPARATIVE METHODS FOR ENANTIOMERIC ENRICHMENT OF NON-RACEMIC ENANTIOMERIC MIXTURES

Different methods for preparative enantiomeric enrichment of non-racem ic enantiomeric mixtures were analysed using twenty-one compounds as e xamples. For the evaluation of the separations the term Efficiency of Enantiomeric Enrichment (EEE) was defined as the ratio of the content of the separable enantiomer (enantiomeric excess) in the enriched and in the initial enantiomeric mixture. It was demonstrated that several phase equilibria can result in enantiomeric enrichment, but for an eff icient separation one of the phases should be solid. Enantiomeric enri chment can be accomplished by similar phase equilibria by the use of l ess than one equivalent of an achiral agent and sometimes this method is more efficient than the use of conventional ones.