Hetero-Diels–Alder reactions of ketones: a high-yielding synthesis of 2,2-disubstituted 2,3-dihydropyran-4-ones
作者:Philip C. Bulman Page、P. Howard Williams、Eric W. Collington、Harry Finch
DOI:10.1039/c39870000756
日期:——
2,2-Disubstituted2,3-dihydropyran-4-ones may be prepared in high yields by the Lewis acid-catalysed hetero-Diels–Alderreactions of electron-rich dienes with ketones bearing strongly electron-withdrawing substituents.
A general and efficient protocol for the high-pressure-promoted hetero-Diels-Alder reactions of activated ketones has been developed. The reactions are successfully achieved by thiourea-derived organocatalysts, and the desired adducts, convenient precursors of δ-lactones, are obtained in good to high yields.