THE FIRST LIQUID-CHROMATOGRAPHIC SEPARATION OF THE (R)-ENANTIOMER AND(S)-ENANTIOMER OF A CHIRAL SILANOL, SILANE AND GERMANE

The racemic mixtures of the muscarinic antagonists cyclohexyl(phenyl) (2-pyrrolidinoethyl)silanol (sila-procyclidine, rac-1), xyl(hydroxymet hyl)phenyl(2-piperidinoethyl)-silane (rac-2) and xyl(hydroxymethyl)phe nyl(2-piperidinoethyl)germane (rac-3) were resolved by analytical liqu id chromatography (HPLC) using chemically modified cellulose (1) or am ylose (2, 3) as the chiral stationary phase. This chromatographic meth od was used for the quantitative determination of enantiomeric purity of the (R)- and (S)-enantiomers of 1-3, which were obtained by prepara tive resolution with chiral auxiliary agents. Furthermore, the enantio meric purity of these samples was established by C-13 NMR studies usin g chiral shift reagents. According to these studies, the resolved anti podes of 1-3 (obtained by preparative resolution) were almost enantiom erically pure [HPLC: greater than or equal to 98.2% ee ((R)-3) to 99.4 % ee ((R)-1, (S)-1); NMR: greater than or equal to 97% ee].