Separation of the enantiomers of 2-phenylcyclopropanecarboxylate esters bycapillary gas chromatography on derivatized cyclodextrin stationary phases

Separation of the enantiomers of 2-phenylcyclopropanecarboxylate esters has been investigated on derivatized cyclodextrin chiral stationary phases (CD CSPs) to enable direct determination of the enantiomeric purity of the pro ducts of enantioselective cyclopropanation. Four stereoisomers of these chi ral compounds could be resolved to baseline on permethylated P-cyclodextrin CSP. Some unusual phenomena, iso-enthalpy retention behavior and entropica lly driven chiral separation, were observed for the enantioseparation of 2- phenylcyclopropanecarboxylates on the CD CSPs. Thermodynamic parameters wer e evaluated and an enthalpy-entropy compensation effect was observed for n- alkyl esters of 2-phenylcyclopropanecarboxylate separated on CD CSPs.