POLYMER-ANALOGOUS DENITRATION OF POLYSACCHARIDE NITRATES: A STUDY OF SOME REDUCTIVE METHODS WITH MODEL COMPOUNDS AND CELLULOSE NITRATE

Abstract

Crystalline D-mannitol penta- and hexa-nitrates, methyl-β-D-glucopyranoside tetranitrate, and maltose and cellobiose octanitrates were prepared as model substances of known constitution for study of denitration reactions possibly applicable to polysaccharide nitrates. Heterogeneous catalytic hydrogenation smoothly regenerated the parent carbohydrates from the model compounds in nearly quantitative yield and removed 0.42 and 0.63 nitrate groups per glucose unit from cellulose nitrates of 13.3 and 10.7% N respectively. Raney nickel was conveniently removed from the hydrogenated cellulose nitrates by means of a magnet. The action of methyl magnesium iodide, lithium aluminum hydride, or low-pressure hydrogenation with a homogeneous cupric acetate catalyst caused less complete denitration of the mannitol or cellobiose polynitrates. The nitration–fractionation–denitration sequence as a means of isolation of undegraded polysaccharides from natural sources is discussed.