Ab initio study of rearrangement of allenic acids

Epoxidation reactions of dienoic acids (3a and 3b) with DMDO in two different conditions were studied using ab initio Hartree-Fock calculation and 6-31+G* base. Three reaction paths from 3a to 4a were found when DMDO is formed in situ and two reaction paths from 3a to 5a when DMDO is formed in excess. Geometrical parameter as the spiro angle were used to determine its influence in the epoxidation reaction. On the other hand, six combinations in the reaction path from 3b to 5b are found, however, only three have been proposed. Finally, two reaction paths of dehydration of 5b to produce 6b were studied.