Novel synthesis of aryl 2,3,4,6-tetra-O-acetyl-D-glucopyranosides
Abstract
The glycosidation of phenols with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl fluoride in the presence of BF3·OEt2 to give, predominantly, α-anomers has been studied. In the presence of an amine base, 1,1,3,3-tetramethylguanidine, however, enhanced β-selectivity was achieved. The former reaction provides a novel and useful synthesis of aryl 2,3,4,6-tetra-O-acetyl-α-D-glucopyranoside whilst the latter is effective for the glycosidation of relatively hindered phenols.