Theoretical study on alkylation and esterification of methyl 3,6-anhydro-α-D-galactopyranoside

Abstract

Molecular mechanics and ab initio molecular orbital calculations were performed on the neutral and anionic forms of methyl 3,6-anhydro-α-D-galactopyranoside. Results from these calculations suggest that in alkylation and esterification the higher reactivity at O(4) than at O(2) is due to the stabilization of the corresponding anion rather than to steric hindrance. This conclusion is also supported by results from the comparison of the calculated molecular surfaces exposed to nucleophilic attack at these particular positions.