ELECTROCHEMICAL REDUCTION OF TETRA-O-ACETYL-ALPHA D-GLUCOPYRANOSYL BROMIDE - A MILD AND QUANTITATIVE SYNTHESIS OF A GLYCAL

The electroreduction of tetra-O-acetyl-α-D-glucopyranosyl bromide (1) has been studied in dipolar aprotic solvents at mercury electrodes. The overall electrode process is a two electron C-Br bond cleavage coupled to a very fast elimination of acetate ion. Macroreduction afforded tri-O-acetyl-D-glucal (2) as the major product, two co-products arising from father-son reactions. In the presence of acetic acid, however, (2) was quantitatively formed