Three competitive dissociation pathways of glyoxalate

Three possible lower barrier dissociation pathways of the deportonated glyoxylic acid in aqueous solution are predicated by means of B3LYP and CCSD(T) (single-point) methods. The calculated results suggest that the formation of formate ion is the energetically most favorable process, and that the decomposition reaction is occurring through nucleophilic attack of negatively charged carboxylic oxygen on the α-carbon. This is in good agreement with the proposed mechanisms of the mass spectrometry experiment.