An achiral deuterated derivatizing agent for enantiomeric analysis through NMR in a liquid crystalline solvent

The application of a 'deuterium probe' for the enantiomeric analysis of chiral amines, aminoacids and alcohols is proposed. The probe is the perdeuterated benzoyl fragment which can easily and reversibly be attached to the corresponding materials. The analysis is performed through measurements of the differential ordering effect (DOE) in the deuterium NMR of the chiral material dissolved in a cholesteric-nematic liquid crystalline system. Since all the chiral compounds which we studied were not racemic, the assignments of the observed DOE's to the enantiomers enabled us to draw tentative conclusions relating the results to the absolute configurations. This may open the way for the empirical derivation of absolute configurations of enantiomers from DOE measurements. (C) 1997 Elsevier Science Ltd. All rights reserved.