Partial Methylation with Diazomethane of the Sugar Moiety of Some C- and O-D-Glucopyranosides

Abstract

On treatment of some C-and O-D-glucopyranosides with diazomethane in methanol or in methanol-dimethylformamide mixture, a partial methylation of the sugar moiety took place, though to a slight extent, to give a mixture of methyl ethers, in which 3-methyl ether is the major. The reaction is much favored in the presence of a small amount of stannous chloride. A O-α-D-glucopyranoside gave almost exclusively the corresponding 3-methyl ether of the glucose residue, while the β-anomer provided, beside 3-methyl ether, 2, 3-dimethyl ether nearly in equal amount. The benzylidene derivatives of O-α-and β-D-glucosides gave also the corresponding 3-methyl ether but 2, 3-dimethyl ether was formed only in trace and, instead, 2-methyl ether was provided.