THE MECHANISM FOR THE CONVERSION OF URIC ACID INTO ALLANTOIN AND DEHYDRO-ALLANTOIN. A NEW LOOK AT AN OLD PROBLEM

Article abstract of DOI:10.1016/S0040-4020(01)87480-9

The reaction of uric acids 1 with iodine in alkaline solution yields, on acidification, new dehydroallantoins 11, or normal oxidation products, allantoins 13, depending on whether an excess or a stoichiometric amount of oxidant was used.The structure and regiochemistry of dehydro-allantoins 11 was established by chemical, spectroscopic, and 14C-labelling methods.These experimental results, in combination with other data, generate a new mechanistic scheme for the uricolytic pathway to allantoin, ruling out the intervention of a symmetrical transition state prior to the decarboxylation step.