COMPETITION BETWEEN DECARBOXYLATION AND ISOMERIZATION IN THE C3H5O2(1+) ENERGY SURFACE. JUSTIFICATION OF THE EXPERIMENTAL RESULTS BY MOLECULAR ORBITAL CALCULATIONS ON THE SOLVATED IONS

Article abstract of DOI:10.1002/poc.610070502

In contrast with recent molecular orbital calculations on the decarboxylation of O-protonated 2-oxetanone, this experimental work indicates that no decarboxylation of this cation occurs in sulphuric acid solution up to 150 deg C, but instead a clean isomerization to protonated acrylic acid takes place.Parallel theoretical work shows that the gas-phase model is too crude to account successfully for the experimental facts obtained in acidic media.However, the latter are well reproduced when the effect of the solvent is taken into account.The present findings do not necessarily invalidate the reaction mechanism currently accepted to explain the rate enhancement and change of stereochemistry accompanying the decarboxylation of 3,4-disubstituted 2-oxetanones under acid catalysis.