Ab initio energetics of nonsubstituted monocyclic pyrones

The monocyclic nonsubstituted pyrones were studied computationally using state-of-the-art ab initio composite computational techniques. Combination of the accurate energies so obtained with conveniently chosen isodesmic or homodesmotic chemical reactions lead to very confident predictions of their corresponding standard enthalpy of formation. The internal consistency of the results obtained from a vast number of independent chemical schemes serves as a further support of the quality of our results, which are thus proposed to establish the energetics of α-pyrone and γ-pyrone.