Gas chromatographic enantiomer separation of chiral ketones — Order of elution and configurational stability of oxime derivatives

Summary Oximes of chiral ketones can be separated into enantiomers by capillary gas chromatography on the chiral polysiloxanes XE-60-L-valine-(S)- or (R)--phenylethylamide. Usually predominantly E-isomers are formed and are better separated than Z-isomers. From time-dependent gas chromatographic measurements it can be concluded that the oximes are configurationally stable and that racemization during oxime formation is negligible. The order of elution of enantiomers depends on the structure of the ketone and is different for aliphatic and alicyclic compounds.