A computational study of base-catalyzed reactions of cyclic 1,2-diones: cyclobutane-1,2-dione.

Autor: Sultana N; Department of Chemistry, University of Sargodha, Sargodha, Pakistan ; Institut für Chemie, Karl Franzens Universität Graz, Heinrichstr. 28, A-8010 Graz, Austria., Fabian WM
Jazyk: angličtina
Zdroj: Beilstein journal of organic chemistry [Beilstein J Org Chem] 2013 Mar 21; Vol. 9, pp. 594-601. Date of Electronic Publication: 2013 Mar 21 (Print Publication: 2013).
DOI: 10.3762/bjoc.9.64
Abstrakt: The reaction of cyclobutane-1,2-dione with hydroxide was studied by a variety of ab initio (MP2, SCS-MP2, CCSD(T), CEPA/1) and density functional (M06-2X) methods. Three possible reaction paths of the initially formed tetrahedral adduct leading to either 1-hydroxycyclopropane-1-carboxylate (benzilic acid type rearrangement, path A), α-oxobutanoate (path B) or γ-oxobutanoate (path C) were considered. Although the latter two products show similar or even more negative Gibbs free energies of reaction than calculated for the benzilic acid type rearrangement, the Gibbs free energies of activation are substantially higher. According to the calculations, the only feasible reaction appears to be the formation of 1-hydroxycyclopropane-1-carboxylate, which is corroborated by previous experimental observations.
Databáze: MEDLINE