Studies on L-Gulonic Acid Derivatives. III. Synthesis of Benzyl 2, 4, 5, 6-Tetra-O-benzyl-L-gulonate and Its Oxidation

Abstract

Synthesis of benzyl 2, 4, 5, 6-tetra-O-benzyl-L-gulonate (IX), a prospective starting material leading to β-keto-L-gulonic acid (II), was described. Oxidation of IX with the Pfitzner-Moffatt reagent gave a mixture of β-keto esters (X, XI) epimeric at C-2 and their enol-form, which was debenzylated by catalytic hydrogenation to afford L-xylulose (III), decarboxylation product of II, as the principal product and probably 2, 3-diketo-L-gulonic acid (XII).