THE ALICYCLIC RING-CLEAVAGE AND OTHER TRANSFORMATIONS OF PERFLUORINATED 1-ALKYL-BENZOCYCLOBUTENE, 1,1-DIALKYL-BENZOCYCLOBUTENE AND 1,2-DIALKYL-BENZOCYCLOBUTENE IN THE SYSTEM BR-2-SBF5

In the reactions of perfluorinated 1-methyl- (2) and 1-ethyl-benzocycl obutene (3) with bromine in an SbF5 medium, cleavage of the four-membe red ring of the starting compounds giving 2-bromoperfluoroisopropylben zene (8) and 2-bromoperfluoro-sec-butylbenzene (9), respectively, was observed. In the system Br-2-SbF5, perfluorinated 1,1- (4) and 1,2-die thylbenzocyclobutene (5) undergo bromofluorination of the aromatic rin g and breaking of the C-1-C-2 bond of the four-membered ring. Thus, in the Br-2-SbF5, system, compound 5 gives 4-bromoperfluoro-1,2-dipropyl cyclohexene (10) and perfluoro-1,2-dipropylcyclohexene (11), and isome r 4 gives oro-1,1-diethyl-3,4,5,6-tetrahydrobenzocyclobutene (15) and perfluoro-1-methyl-2-(pent-2-ene-3-yl)cyclohexene (16). The latter is obtained by heating compound 15 with SbF5 or CsF.