Assignement of the configuration of optical isomers by gas chromatography with asymmetric phases. The order of emergence of amino-alkanes, and α-, β-, and γ-amino-acids on carbonylbis-(N-L-valine isopropyl ester)

Abstract

The interaction of the enantiomers of N-trifluoroacetyl derivatives of amines and α-, β-, and γ-amino-acid esters with the optically active stationary phase carbonylbis-(N-L-valine isopropyl ester) has been studied systematically by g.l.c. The general formula of the solutes is CF₃·CO·NH·C*HR¹R², in which R¹= alkyl and R² is either a different alkyl group or an ester-bearing substituent. When the solute molecules are viewed in the direction from the asymmetric carbon to the nitrogen atom, the other three substituents are seen to be arranged, according to decreasing size, in either a clockwise or an anticlockwise direction, depending on the enantiomer considered. The enantiomers with the clockwise arrangement have been found to have throughout the larger retention time on the L-phase studied. The magnitude of the resolution factor increases with the difference in size between R¹ and R².