Photochemical conversion of the o-nitrobenzyl-C-glucoside to a sugar lactone

A new family of activated glycosidic compounds has been designed and synthesized: (2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-2-nitrophenylmethane (1). It is stable in conditions commonly used for synthesis, and it can be converted to a sugar lactone derivative merely by photoirradiation (λ=365 nm): 2,3,4,6-tetra-O-acetyl-D-glucono-1,5-lactone (2). A mechanism for the reaction is proposed. The photochemical conversion of 1 in the presence of methanol has also been demonstrated, giving rise to methyl 2,3,4,6-tetra-O-acetyl-D-gluconate (3).