Abstract

The high acidity of Meldrum’s acid, barbituric and tetronic acids in comparison to their acyclic analogues was explained by density functional
theory and calculations and by natural bond orbital analysis. The present study shows that cyclic -dicarbonyl compounds are remarkably
stabilized by intramolecular donor-acceptor interactions and this effect is absent in their acyclic analogues.

Key words: Meldrum’s acid, barbituric acid, tetronic acid, carbon acidity donor-acceptor interactions, DFT calculations, NBO analysis.