Solvent-dependent, kinetically controlled stereoselective synthesis of 3- and 4-thioglycosides.

Facile approaches to prepare 3- and 4-thioglycosides of the galacto, gulo, and gluco type from the parent triflates are presented. The dependencies of the solvent and the protecting group pattern, as well as the configuration of the neighboring and leaving groups, have been studied for these reactions. The results clearly show that the efficient stereoselective synthesis of methyl 3-thio-galactoside depends highly on the solvent and the nucleophile concentration.