A Dft Pursuit on Tandem Cycloaddition-Cycloreversion of 2-Pyrone and 1,4-Oxazinone with Strained Alkynes

Abstract

2-Pyrone (2P) and 1,4-oxazinone (OXZ) react with strained alkynes viz., cyclohexyne (SA1), benzyne (SA2) and pyridyne (SA3) through concerted cycloaddition-cycloreversion reaction. All the reactions have been scanned and the activation parameters, FOE, deformation energies and variation in aromaticity computed at B3LYP/6-31g(d) level.The obtained results have been compared with that of acetylene. In SA1,faster cycloadditionis explained by its strain, in addition,aromatic gain is accountable to enhance the rate of cycloaddition in SA2 and SA3.