Synthesis of Heterocyclic Systems by Transition-Metal-Catalyzed Cyclization-Migration Reactions – A Diversity-Oriented Strategy for the Construction of Spirocyclic 3(2H)-Furanones and 3-Pyrrolones
作者:Jörg T. Binder、Benedikt Crone、Stefan F. Kirsch、Clémence Liébert、Helge Menz
DOI:10.1002/ejoc.200601060
日期:2007.4
proceed through an oxonium ionintermediate B, which triggers a stereospecific 1,2-shift analogous to an α-ketol rearrangement. When exploited in a different manner, the 2-alkynyl-2-hydroxy carbonyl compounds 1 afford 3-pyrrolones 3 in 33–81 % yield. For this purpose, the starting compounds 1 are treated with primary amines in the presence of 5 mol-% of PtCl2 at 100 °C in a convenient one-pot process. These