Direct Observation of α-Oxo Ketenes Formed from 1,3-Dioxin-4-ones and the Enols of β-Keto Esters

Article abstract of DOI:10.1021/jo00007a008

The enol forms of β-keto esters thermolyze to alcohols and α-oxo ketenes, which are characterized by low-temperature IR spectroscopy and on warming regenerate the β-hydroxy-α,β-unsaturated esters. The matrix isolated s-Z and s-E forms of α-oxo ketenes are characterized and photochemically converted into other conformers or sites.Matrix photolysis of 2,2,6-trimethyl-1,3-dioxin-4-one gives the s-Z acetylketene initially. α-Oxo ketenes polymerize in the cold and dimerize only at elevated temperatures.