6-(3-Guaiazulenyl)-5-isopropyl-3,8-dimethyl-1(6H)-azulenone and Its Norcaradiene-Isomer. Key Intermediates for Novel Intermolecular One-Carbon Transfer in Autoxidation of Guaiazulene

Article abstract of DOI:10.1246/cl.1987.455

Autoxidation of guaiazulene either at 85 deg C in N,N-dimethylformamide-0.5 M sulfuric acid or at 25-35 deg C on the surface of a filter paper yielded, together with other products, the two title compounds which were shown to be in equilibrium and to constitute important intermediates for the intermolecular one-carbon transfer reactions frequently observed during autoxidation of many azulenic hydrocarbons.