Coumarin-enaminoester Adducts: Structure Corrections (X-ray) and Some Novel Transformations. Synthesis of Annulated Tricyclic 2-Pyridones
作者:Ivo C. Ivanov、Lyubomir D. Raev、Wolfgang Frey
DOI:10.1055/s-2004-829081
日期:——
By means of X-ray crystallographic analysis the correct structure of all three types of stable coumarin-enaminoester adducts 6, 10 and 11 and the corresponding spontaneous multistep heterocyclizations of ANRORC-type are reported. The initially formed adducts 3-5 undergo lactone ring opening as well as, in many cases, spontaneous transannular intramolecular Michael addition, to give 6, 10 and 11. A