Synthesis of Quinolinequinones and 1,2,3,4-Tetrahydroquinolinequinones via Cyclobutenediones

Article abstract of DOI:10.1021/jo00022a031

N-Benzyl-1,2,3,4-tetrahydrocyclobutapyridine-5,6-dione is easily synthesized and functions as a synthetic equivalent of the unstable pyridiocyclobutenedione.Regiospecific introduction of unsaturated nucleophiles at the more reactive carbonyl group, followed by thermolysis in xylene in vessels open to air, rapidly establishes the tetrahydroquinolinequinone system which can be oxidized to the corresponding quinolinequinone with 2,3-dichloro-5,6-dicyanoquinone.