The addition of 1,3-diphenylisobenzofuran to cyclooctateraene and to dimethyl cyclooctatetraene-1,2-dicarboxylate. The benzene ring as a dienophile in an intramolecular diels-alder reaction

Article abstract of DOI:10.1246/bcsj.63.395

The reaction of cyclooctatetraene with 1,3-diphenylisobenzofuran afforded two kinds of 1:1 [2π+4π]-cycloadducts, a cage-type 1:1 cycloadduct and two classes of 1:2 cycloadducts. The cage-type compound was formed from one of the [2π+4π]-cycloadducts via an unprecedented second [2π+4π]-cycloaddition reaction in which the double bond of the benzene moiety acted as a dienophile. A similar reaction with dimethyl cyclooctatetraene-1,2-dicarboxylate gave a 1:1 [2π+4π]-cycloadduct and a 1:2 cycloadduct. No cage-type compound was formed.