ChemInform Abstract: Electron‐Transfer‐Induced Rearrangements of Phenylated Tricyclo‐(4.2.0.02,5)octane and 1,5‐Cyclooctadiene.

Abstract

ChemInform Abstract Irradiation of 1,2-diphenylcyclobutene (II), obtained by treatment of 1,2-dibenzoylethane (I) with titanium tetrachloride and zinc powder, leads to the formation of the tetraphenyltricyclo(4.2.0.0)octane (III). This is isomerized to form the tetraphenyl-1,5-cyclooctadiene (IV) and the tetraphenyltricyclo(3.3.0.0)octane (V) via a cation radical reaction upon photolysis in the presence of 9,10-dicyanoanthracene (DCA) as the photosensitizer. The compound (V) is also obtained by irradiation of (IV) in the presence of DCA. (Mechanism).