“…a coupling compound 1.1' -bipyrene (via, apparently, a free-radical intermediate), some pyrenic acid and other ring-degradation products. 692 Active manganese dioxide was the reagent of choice for the oxidation of the isomeric adducts. following the condensation of 1,2,3,4-and 1.2,3,8-tetramethylcyclooctatetraenes with N-phenyltriazolinedione 693 ; similar isomeric adducts of the dimethylcyclooctatetraene derivatives were also oxidized with manganese dioxide.…”