FLUORENONE 1,4-DIHYDROPYRIDINE DERIVATIVES WITH CARDIODEPRESSANT ACTIVITY - ENANTIOMERIC SEPARATION BY CHIRAL HPLC AND CONFORMATIONAL ASPECTS

The direct HPLC enantiomeric separation of five fluorenone-1,4-dihydro pyridine-3,5-dicarboxylic diesters has been achieved using a Chiralpak AD stationary phase obtaining simultaneously good enantioselectivitie s, resolution factors, and elution times, CD spectra of the individual enantiomers for two compounds were measured. Thermodynamic parameters associated with the adsorption equilibria of the enantiomers with the chiral stationary phase were obtained from HPLC runs at various tempe ratures. The conformational preferences of the synperiplanar fluorenon e group and of the cis/cis ester groups were obtained by H-1 NMR spect ra, including NOE experiments. (C) 1996 Wiley-Liss, Inc.