Synthesis of γ,γ-Disubstituted Butenolides through a Doubly Vinylogous Organocatalytic Cycloaddition
作者:Anna Skrzyńska、Piotr Drelich、Sebastian Frankowski、Łukasz Albrecht
DOI:10.1002/chem.201804650
日期:2018.11.7
organocatalytic approach to γ,γ‐disubstituted butenolides is described. It is based on a fully site‐selective functionalization of 5‐alkylidenefuran‐2(5H)‐ones via trienamine‐mediated [4+2]‐cycloaddition with α,β,γ,δ‐diunsaturated aldehydes. The developed methodology proceeds with excellent stereocontrol and constitutes a unique example of trienamine chemistry with vinylogous dienophiles. Importantly,
Gasphase thermolysis above 220° of 2(3H)-oxepinones 2 and 2(3H)-furanones 5 gives carbon monoxide and the corresponding unsaturated carbonyl compounds 3, 4 and 6. The preparative value of these cheletropic processes is demonstrated.