Oxidation of certain cyclic carbonyl compounds with alkaline hydrogen peroxide

The following cyclic compounds were oxidized at 4° by means of aqueous sodium peroxide in large excess: 2,3,4,6/5-pentahydroxycyclohexanone (1); xylo-pentahydroxy-2-cyclohexen-l-one (2); xylo-trihydroxycyclohexane-1,2,3-trione (3); reductic acid (4); and ninhydrin (5). On oxidation, 1, 2, and 3 gave carbon dioxide, formic acid, and oxalic acid; in addition, 1 yielded DL-glucaric acid, and 2 and 3 afforded xylaric acid. Compound 4 gave almost equimolecular quantities of carbon dioxide and succinic acid. In addition to a small amount of formic acid, compound 5 gave carbon dioxide and phthalic acid in yields of 92 and 95%, respectively. Reaction mechanisms are proposed.