Solvent effect on the isomeric equilibrium of carbohydrates: the superior ability of 2,2,2-trifluoroethanol for intramolecular hydrogen bond stabilization.

ABSTRACT

The higher aptitude of 2,2,2-trifluoroethanol for intramolecular hydrogen bond stabilization in carbohydrates is suggested. This belief, arising from the analysis by 1H NMR spectroscopy of the solvent effect of D2O, DMSO-d6, and 2,2,2-trifluoroethanol-d3 on the isomeric equilibrium of caryophyllose, was also confirmed by shifting of the conformational equilibria of beta-ribopyranose and of its methyl glycoside.