Kinetics of the decarboxylation of dihydroxyfumaric acid

Abstract

All β-keto acids are unstable in aqueous solution and spontaneously lose carbon dioxide. Dihydroxyfumaric acid ketonises in aqueous solution to a β-keto acid - and so the decomposition of this group of acids will be considered in some detail. Pedersen K. J. Pedersen, Acta Chem. Scand., 9, l640) (l955). investigated the decomposition of αα-dimethyl acetoacetic acid which can exist only in the keto form. He compared his results with those for acetoacetic acid and found that undissociated dimethyl acetoacetic acid decomposed 4-5 times faster than undissociated acetoacetic acid, indicating that the keto form is unstable.(Steinberger and Westheimer have also found that dimethyl oxaloacetic acid which only exists in the keto form decarboxylates readily H.J. H. Fenton, J., 1570 (1912).