INTEGRAL-EQUATION AND AB-INITIO STUDY OF THE EFFECT OF SOLVATION ON ANOMERIC EQUILIBRIA IN AQUEOUS-SOLUTION - APPLICATION TO 4,6-DIMETHYL-2-METHOXYTETRAHYDROPYRAN

A number of models are used to study the structure and energetics of t he axial and equatorial anomers of 4,6-dimethyl-2-methoxytetrahydropyr an in aqueous solution, to understand the observed preferential solvat ion of the equatorial form. Both quantum mechanical continuum and supe rmolecule treatments predict this effect qualitatively, but lead to it s underestimation, suggesting the need for both long-range interaction s and explicit solvent. A reference interaction site model, which incl udes both effects and uses a classical potential, is successful in qua ntitatively predicting such differential solvation, the result being l ess satisfactory when the solute is modeled quantum mechanically.