Carbohydrate Stereochemistry, and NMR Spectroscopy

Abstract

This opening presentation is intended to draw attention to several aspects of carbohydrate stereochemistry that can profitably be examined by NMR spectroscopy which, as a consequence, has contributed abundantly to modern developments in the carbohydrate field. Some of the NMR applications are to be treated in greater depth by other participants in this symposium. Measurements of chemical shift, spin-spin coupling, relaxation parameters, and nuclear Overhauser enhancement are all utilized for the purpose. Among the kinds of stereochemical information accessible from NMR data are: configurational assignment, molecular conformation (including solvent influences), a comparison of solution and solid state conformations, orientation of substituent groups, and the geometry of interactions between a carbohydrate and other species. Examples of several of these are cited from our own work, and emphasis is given to certain observations that, although widely recognized for some time, are not well understood. Hopefully, this reminder will stimulate a further assessment, and a clarification, of those points.