Process for selective oxidation of primary alcohols and novel carbohydrate aldehydes

摘要

A process for oxidizing a primary alcohol uses a nitroxyl compound with an oxidizing agent in an aqueous medium or in a mixture of water with an alcohol, an ether or water immiscible organic solvent. The primary alcohol is oxidized in the presence of an enzyme capable of oxidation and/or in the presence of a complex of a transition metal mimicking an enzyme The nitroxyl compound can be is a di-tert nitroxyl compound such as 2,2,6,6-tetramethylpiperidin-1-oxyl. The enzyme can be an oxidoreductase such as a peroxidase and the oxidizing agent can be hydrogen peroxide or oxygen. An oxidized carbohydrate can be an oligosaccharide or polysaccharide of the a-glucan, mannan, galactan, fructan or chitin types or carbohydrate glycosides containing at least 1 cyclic non- galactose monosaccharide chain group carrying a carbaldehyde group per 25 monosaccharide units and per average molecule or a disaccharide, oligosaccharide or polysaccharide of the b-glucan types containing at least 1 cyclic monosaccharide chain group carrying a carbaldehyde group per 25 monosaccharide units and per average molecule and further containing carboxylmethyl groups.