Reaction of Polyhaloalkyl-Substituted Chromones, Pyrones, and Furanones with Salicylaldehydes as a Direct Route to Fused 2H-Chromenes
journal contributionposted on 2006-06-09, 00:00 authored by Vyacheslav Ya. Sosnovskikh, Vladislav Yu. Korotaev, Dmitry L. Chizhov, Igor B. Kutyashev, Danil S. Yachevskii, Olga N. Kazheva, Oleg A. Dyachenko, Valery N. Charushin
Polyhaloalkyl-substituted chromones, γ-pyrones, and β-furanones react with salicylaldehydes in the presence of piperidine to give a wide variety of fused 2H-chromenes in good yields. This novel annulation reaction presumably proceeds by a tandem intermolecular oxa-Michael addition and subsequent intramolecular Mannich condensation.