OXIDATIVE CLEAVAGE OF THE C-C BOND IN PROCESSES INVOLVING THE HETEROAROMATIZATION OF 9R-SYM-NONAHYDRO-10-OXA(CHALCOGENA)ANTHRACENES

The reaction of 9-(2-methoxyphenyl)- and 9-(2-thienyl)-sym-nonahydro-10-selena(thia)anthracenes with trifluoroacetic acid causes their heteroaromatization with the elimination of substituents from the γ positions of the heterorings. A similar transformation of these compounds, as well as their oxygen and 9-benzyl-substituted analogs, occurs during anode electrochemical oxidation. The stepwise character of the cleavage of the C-C bond, which includes one-electron oxidation of the chalogenapyrans and subsequent fragmentation of the cation-radical intermediates, is substantiated.