SEPARATION OF THE 4 STEREOISOMERS OF Z11556A, INTERMEDIATE IN THE SYNTHESIS OF TRIAZOLE ANTIMYCOTICS, BY CAPILLARY ELECTROPHORESIS

Z11556A, a key intermediate in the synthesis of triazole antimycotics, was resolved into its four stereoisomers by high-performance capillar y electrophoresis. It migrates retarded with respect to the electrosmo tic flow since it is negatively charged at mild alkaline pH. The selec tivity of a number of native and derivatized cyclodextrins was screene d and beta-cyclodextrin turned out to be the only effective. An extens ive optimization of the cyclodextrin concentration, of the type and am ount of the organic modifier, of the buffer pH and molarity, and of th e applied voltage led to baseline separations (resolution factors from 2.0-3.0) among all of the four stereoisomers. The reproducibility of the assay was also evaluated.