cis-and trans-2, 5-Dimethoxytetrahydropyrans, cis-2, 5-dimethoxy-6-methyltetrahydropyran and 2-methoxy-5-methyltetrahydropyran have been examined to see the effect of an OCH3 group at position 5 on the degree of anomeric effect in substituted 2- methoxytetrahydropyrans. The present study shows that this group stabilises the C-2 electronegative substituent in the axial position. Semi-empirical and ab initio molecular ...