Ditritylation of Methyl and Benzyl α-<scp>d</scp>-Gluco-, -Manno-, and -Galactopyranosides and Preparation of Their Partially Benzylated Derivatives

Abstract

Abstract The ditritylation of methyl and benzyl α-d-gluco-, -manno-, and -galactopyranosides with trityl chloride in pyridine at 70 °C proceeds in a regioselective manner to give the 2,6-ditrityl ethers of the glucosides, the 3,6-ones of the mannosides, and both 2,6- and 3,6-ones of the galactosides. The rearrangement of the trityl group from O-3 to O-2 of the mannosides at 100 °C causes the selective formation of the 2,6-ditrityl ethers. From the 2,6- and the 3,6-ditrityl ethers, the 3,4- and 2,4-dibenzyl ethers of the hexopyranosides are prepared.