Liquid chromatographic resolution of 2-hydroxycarboxylic acids on a new chiral stationary phase derived from (S)-leucine.
Enantiomers of racemic 2-hydroxycarboxylic acids have been resolved as their O-ethoxycarbonyl pi-basic anilide derivatives on a new chiral stationary phase (CSP) derived from N-(3,5-dinitrobenzoyl)leucine N-phenyl N-alkylamide and the resolution results have been compared with those on various commercial pi-acidic CSPs. The resolution results demonstrate that the new CSP derived from N-(3,5-dinitrobenzoyl)leucine N-phenyl N-alkylamide is most effective among the five CSPs tested for the resolution of 2-hydroxycarboxylic acid derivatives. In order to elucidate the chiral recognition mechanism exerted by the new CSP, the resolution of slightly differently modified derivatives of 2-hydroxycarboxylic acids on the new CSP has been investigated. Based on the resolution results, a chiral recognition mechanism utilizing three simultaneous interactions such as the face to face pi-pi interaction and the two hydrogen bonding interactions between the CSP and the more retained enantiomer of the analyte has been proposed.
Hyun
M H
MH
Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, South Korea.
Kang
M H
MH
Han
S C
SC
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006880:Hydroxy Acids / Q000737:chemistry / Q000302:isolation & purification*; D007202:Indicators and Reagents; D013237:Stereoisomerism
D006880:Hydroxy Acids; D007202:Indicators and Reagents