Oxidation of Dicarbonyl Compounds to Carboxylic Acids

Cyclic a-diketones and o-quinones give, under comparable conditions, dicarboxylic acids. P-Naphthoquinone is converted in 83% yield into o-carboxyallocinnamic acid by 9% peroxyacetic acid in an exothermic reaction [277] (equation 393). 

The treatment of tetrafluoro-o-benzoquinone with 40% peroxyacetic acid at 70-75 °C for 4.75 h degrades the quinone to difluoromaleic acid in 55% yield. The same acid is obtained in 59% yield under similar conditions from fluoranil (tetrafluoro-p-benzoquinone) [273]. 

The oxidation of p-diketones and p-keto esters with peroxyacetic acid [270] and peroxyphthalic acid [333] leads to complex products that ultimately undergo hydrolysis. In the case of acetylacetone, the products are acetic acid and pyruvic acid [270] (equation 452). 

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