Conformational analysis in carbohydrate chemistry. I. Conformational free energies. The conformations and α : β ratios of aldopyranoses in aqueous solution

Abstract

The relative free energies of the aldopyranoses in aqueous solution have been calculated, taking non-bonded interaction energies and the anomeric effect into account. It is shown that the calculated free-energy values correctly predict the predominant conformation of the a- and ß-pyranose forms of each aldose. The a- to ß-pyranose ratios of the aldoses in aqueous solution, calculated from these values, are in reasonable agreement with those determined experimentally.