Synthesis, Reactions and Thermal Properties of endo-5,12:endo-6,11-Dietheno-5,5a,6,11,11a,12-hexahydronaphthacene

Article abstract of DOI:10.1016/0040-4020(95)00041-6

The title compound 6 was synthesized in nine steps, starting from the Diels-Alder adduct 21 of ketomethanoethanonaphthalene 20 and p-benzoquinone, via 7,8-dimethylidenediethenoanthracene 10 followed by Diels-Alder reaction with (E)-bis(phenylsulfonyl)ethylene and aromatization.Photocyclization of 6 led to 32 via an intramolecular <2+2> cycloaddition.Hydrogenation and epoxidation of 6 gave the corresponding bis-benzo hydrocarbon 33 and bis-epoxide 34.Bromination of 6 proceeded by transannular reaction to produce N-type exo, endo dibromide 35b and U-type exo, exo dibromide 36b.Compound 6 underwent thermal decomposition at 210 +/- 5 deg C to form naphthalene and benzobarrelene.