Intramolecular hydrogen-bonding in phenyl mono-, di-, and tri- O-methyl-β- d-glucopyranosides

Abstract

I.r spectroscopy has been used to obtain frequency shifts and integrated intensities of the hydroxyl-stretching vibration band for intramolecular hydrogen-bonding in 14 phenyl mono-, di-, and tri- O-methyl-β- d-glucopyranosides in solution in dilute carbon tetrachloride. Intramolecular hydrogen-bonding with characteristic differences were exhibited by these compounds and the results were interpreted in terms of the conformation of the hydroxyl group. For p-substituted phenyl 3,4,6-tri- O-methyl-β- d-glucopyranosides, the hydroxyl-stretching vibration bands were also measured for dilute solutions in carbon tetrachloride, and a linear relationship was found between the shift to a lower wave number and the Hammett σ p constant. This shift was attributed to intramolecular hydrogen-bonding between HO-2 and O-1 which has a weaker proton-accepting ability than that of MeO-3.