Abstract: Thermal decompositions of tert-butyl 2, 3-benzonorcaradiene-7-percarboxylate (7, tert-butyl 2, 3-(2', 3'-naphtha)-norcaradiene-7-percarboxylate (8), bis (2, 3- benzonorcaradiene-7-carbonyl) peroxide (9), and bis [2, 3-(2', 3'-naphtho) norcaradiene-7- carbonyl] peroxide (10) have been studied with particular attention paid to the hydrocarbon products, 2, 3-benzonorcaradiene (1 1) and I, 2-benzotropilidene (12) from 7 and 9, and 2, ...