ChemInform Abstract: Intramolecular Cyclization of 9,10-Anthraquinones Promoted by Reaction with Halogenophosphoranes

The results of the research of an unknown reaction of halogenophosphoranes (Ia-Ie) with peri-oxy(amino)-9,10-anthraquinones leading to the formation of anthrones (Via-Ie, XIII) and tetrahydroanthracenes (XIa,b) are reported. The scheme of reaction includes the formation of phosphabenzanthrone (V) and anthraquinone (III) which was fixed by a low temperature 31p NMR spectroscopy. The driving force of discovered reaction of anthraquinone cyclization is explained by specific character of transference of electronic influence from substituents to a carbonyl group contained in anthraquinones. Certain properties of products formed having an unusual structure from the viewpoint of the chemistry of anthraquinones are described.