Reactions of Tropone Tosylhydrazone Sodium Salt with Anthracene, 1,3-Diphenylisobenzofuran, and Phenylacetylene: and Type Cycloaddition Reactions of Cycloheptatrienylidene or 1,2,4,6-Cycloheptatetraene

Article abstract of DOI:10.1246/bcsj.58.1663

The reaction of tropone tosylhydrazone sodium salt (1) with anthracene gave a <4+2>-type adduct and the reaction of 1 with 1,3-diphenylisobenzofuran afforded endo- and exo-<4+2>-type adducts as well as a heptafulvene derivative.The reaction of 1 with phenylacetylene yielded a <2+2>-type adduct, which rearranged into 2-phenylindene upon heating.The addition reactions are thought to proceed via the allene intermediate, 1,2,4,6-cycloheptatetraene, which is a valence-bond isomer of the carbene intermediate, cycloheptatrienylidene, initially generated by the pyrolysis of 1.The photoreaction of adduct 3 with a high-pressure mercury lamp afforded a ring-closure product via the photobicyclization reaction of the cycloheptatriene moiety of the adduct.Thermal interconversions between the three products of the reaction of 1 with 1,3-diphenylisobenzofuran were investigated.