Liquid Chromatographic Resolution of Enantiomeric Dipeptides on the Chiral Stationary Phase Derived from (S)-1-(6,7-Dimethyl-1-naphthyl)isobutylamine

Liquid chromatographic resolution of fifteen enantiomeric dipeptide methyl esters as their N-3,5-dinitrobenzoyl derivatives was investigated on the chiral stationary phase (CSP) derived from (S)-1-(6,7-dimethyl-1-naphthyl)isobutylamine. The four stereoisomers present in each dipeptide derivative were observed to be separated quite well with the (R,R) isomer being eluted first. The separation factors for two enantiomeric pairs such as (R,R)/(S,S) and (R,S)/(S,R) and the elution orders are explained by two competing “opposite-sense” chiral recognition mechanisms.