Investigation of the Hydrogen Bonding Properties of a Series of Monosaccharides in Aqueous Media by 1H NMR and IR Spectroscopy

Abstract

A technique, based on 1H NMR and IR experiments, to characterise intramolecular hydrogen bonds in aqueous medium in a series of amino, amido and ammonium sugar derivatives has been established. Three groups of molecules, representing amides (4, 5 and 6), amines (7 and 8) and ammonium salts (chlorides 9 and 10, and phosphates 11 and 12), with different relative configurations of their functional groups, have been investigated to assess the effect of the nature and the stereochemistry of these groups on the hydrogen-bonding features of the sugar. The deduced features in water solution are compared to those obtained previously in nonpolar solvents. The phosphate salts of amines 7 and 8 (11 and 12) were also prepared, in order to evaluate the influence of the OH groups on the binding of the phosphate counterion, and the possibility of establishing cooperative hydrogen bonds involving the phosphate group. The data presented here indicate that the 1,3-cis-diaxial-type configuration in sugar diols and amino alcohols produces an intramolecular six-membered-ring hydrogen bond that survives in water and, moreover, offers the possibility to establish cooperative intermolecular hydrogen bonds. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)