Chromatographic Separation of the Excess Enantiomer under Achiral Conditions

The excess enantiomer can be separated chromatographically without difficulty from mixtures of enantiomers in the ratio a: b (a ≠ b), as are usually formed in enantioselective syntheses. This is possible on achiral stationary phases and with achiral mobile phases, but only in utilizable amounts if both homochiral as well as heterochiral associates are formed in solution. These associates are diastereomeric. Hence, the stationary phase is of decisive importance. On aminopropyl silica gel the excess entiomer is eluted first, then the racemate.