A Novel Oxidative Cyclization of 2'-Hydroxychalcones to 4,5-Dialkoxyaurones by Thallium(III) Nitrate

Article abstract of DOI:10.1021/jo00125a041

Scope and mechanism studies are reported on a novel oxidative transformation of certain 2'-hydroxy-5'-methoxychalcones to aurones by thallium(II) nitrate (TTN) in alcoholic solvents.A key feature of the reaction is the incorporation of a solvent-derived alkoxy group at C-4 of the aurone.The thermodynamically more stable Z isomers of the aurones are obtained in all cases.Aurones are formed regardless of whether electron donating or electron attracting groups are present at the para position of the B ring of the starting chalcone.