EVALUATION OF A CHIRAL CROWN-ETHER LC COLUMN FOR THE SEPARATION OF RACEMIC AMINES

Enantiomeric resolution of more than fifty racemic primary amines can be achieved on a column that utilizes a crown ether as a chiral selector. The racemic solute is solubilized in an acidic solvent, forming an ammonium ion from the primary amine functional group. An interaction between the lone pair electrons on the oxygens of the crown ether and the positive charge of the ammonium group leads to the formation of an inclusion complex. Due to the chirality of the crown ether there is stereoselective interaction resulting in enantiomeric separation. Excellent resolution is possible for amino acids, amino alcohols, amino esters and amines. Compounds are separated that were poorly resolved by conventional ligand exchange columns and by other means.