The high-temperature alicyclic ring contraction of 1,1-dichloroperfluorotetralin and the alicyclic ring opening of 1,1-dichloroperfluorobenzocyclobutene

The pyrolysis of 1,1-dichloroperfluorotetralin (4) in a stream of argon gives a mixture contained perfluoro-1-methyleneindan (1), perfluoro-3-methylindene (6), 1,1-dichloroperfluoroindan (2) and perfluoroindene (7), while copyrolysis of tetralin 4 with CHClF2 gives a mixture of compounds 1, 6 in the absence of compounds 2 and 7. 1-Chloro-2-(1-chloro-2,2-difluorovinyl)-3,4,5,6-tetrafluorobenzene (12) is formed in the pyrolysis of 1,1-dichloroperfluorobenzocyclobutene (5) in a stream of argon as well as in a stream of CHClF2.