A Simple Preparation of 2,3,4,6-Tetra-O-acyl-Gluco-, Galacto- and Mannopyranoses and Relevant Theoretical Study

The deacylation of glucose, galactose and mannose pentaacetates, galactose and mannose penta(3-bromo)benzoates, as well as the dealkylation of 2,3,4,6-tetra-O-acetyl and 2,3,4,6-tetra-O-(3-bromo)benzoyl methyl alpha-D-glucopyranosides have been studied. In addition, a computational study on the deacylation of alpha-D-glucose pentaacetate has been carried out with density functional theory (B3LYP/6-31G*). The anomeric effect during deacetylation and dealkylation has been clearly demonstrated in both experimental and computational results.