Direct liquid chromatographic enantioseparation of chiral alpha- and beta-aminophosphonic acids employing quinine-derived chiral anion exchangers: determination of enantiomeric excess and verification of absolute configuration

摘要

Four types of quinine-derived chiral anion exchangers were used for the direct liquid chromatographic separation of enantiomers of chiral but N-protected alpha- and beta-aminophosphonic acids. The respective and easily prepared 3,5-dinitrobenzyloxycarbonyl and dinitrophenyl derivatives were well separated, yielding alpha-values between 1.1 and 2.8 and resolution values in the range 2.0-9.0. Besides the chromatographic investigations, data on enantiomeric excesses tees) and the absolute configurations of some enantiomerically enriched alpha- and beta-aminophosphonic acids prepared by stereoselective synthesis were also determined. The results obtained by this method tee and absolute configuration) correspond well with the results previously obtained by a P-31-NMR spectroscopic method. (C)2000 Elsevier Science B.V. All rights reserved. [References: 21]