High-performance liquid chromatographic enantioseparation of 3,5-disubstituted hydantoins analogs and temperature-induced reversals of elution orders on a polysaccharide-based chiral stationary phase.

Enantioseparations were achieved for eleven 3,5-disubstituted hydantoins in HPLC under the normal phase mode using Chiralpak IA. The effects of polar alcoholic modifier and column temperature on retention and enantioseparation were determined. Importantly, we found two kinds of enantiomer elution order (EEO) reversals, which include solvent-induced EEO reversal for compound 9 and temperature-induced EEO reversals for compound 3 and compound 6. The phenomena of these EEO reversals were described for the first time in present work, which is helpful to elucidate the chiral separation mechanism of these hydantoins.