Synthesis of α-Pyrones from Vinylogous Thiol Esters and α-Oxo Ketene Dithioacetals

Article abstract of DOI:10.1021/jo00244a035

Vinylogous thiol esters and α-oxo ketene dithioacetals can be converted into α-pyrones by a strategy involving 1,2-nucleophilic addition of ester, ketone, or hydrazone enolate anions, followed by acid-promoted rearrangement to a δ-keto ester, thiol ester, or acid and subsequent enol lactonization.These multistep procedures can be carried out without isolation and purification of intermediates and afford α-pyrones in good overall yields.The synthetic routes are complementary in terms of substitution patterns and limitations.