A Formal (4 + 2) Cycloaddition of Phosphorus Ylides: Synthesis of Aromatic and Heteroaromatic 1,2-Diesters and Diones.

Heteroarylmethylenephosphorus ylides underwent Michael addition with alkynediones and alkynediesters, followed by intramolecular cyclization and elimination of triphenylphosphine oxide to afford 1,2-diaroylbenzenes and 1,2-alkoxycarbonylcarbo- and heterocycles. The analogous (4 + 2) cycloaddition led to the formation of 2,3-diaroylquinolines.