Models for the assignment of the chemical shifts for protons on the epoxide ring of 2,3-anhydroglycopyranosides

Abstract

The signal assignments for the protons of the epoxide ring in several 3,4-epoxy-2-alkoxytetrahydropyrans have been made by spin decoupling. Because of the close resemblance of these tetrahydropyrans to 2,3-anhydroglycopyranosides, these results have been used to make chemical shift assignments for the H-2 and H-3 protons of the latter compounds. For the compounds examined, the H-2 proton signal occurs at higher field compared to the position of the H-3 proton signal.