OXIDATION OF METHYL ALPHA-D-GLUCOPYRANOSIDE AND SOME RELATED-COMPOUNDS CATALYZED BY NICKEL PEROXIDE

Nickel sulphate efficiently catalyses oxidative glycol cleavage, using sodium hypochlorite as the primary oxidant. Suspended nickel peroxide is assumed to be the active intermediate. 2,3-Butanediol was oxidised (conversion 95%) to acetate at pH <10 and 20 degrees C, applying a mo lar ratio hypochlorite: nickel:diol of 8:0.2:1. Methyl alpha-D-glucopy ranoside was initially oxidised to disodium (R)-2-O-[(R)-carboxylato(m ethoxy) methyl]erythrate. Subsequently oxidation to disodium (R)-2-O-[ (R)-carboxylato (methoxy)methyl]glycerate took place. beta-Cyclodextri n was preferentially oxidatively cleaved (ca. 50%) between the C(2)-C( 3) carbons, although oxidation at the C(6) carbon (ca. 25%) appeared t o occur as well. In contrast, maltodextrin was oxidised at the primary hydroxyl functions.