“Green” oxidation reactions—application to carbohydrate chemistry

Oxidation of glycals by either methyltrioxorhenium (MTO)-hydrogen peroxide or hydrogen peroxide-acetonitrile in methanol provides direct access to methyl glycosides. The two different reagents proceed with a complementary stereochemical outcome enabling the synthesis of [small beta]---pyranosides or [small alpha]---pyranosides from the same carbohydrate precursor.