Reaction of perfluoropropenylbenzene with sulfur trioxide

Depending on the ratio of the reagents and the reaction conditions, the reaction of perfluoropropenylbenzene with SO₃ in the presence of BF₃ or SbF₅ gives perfluoro--phenylallyl fluorosulfate or perfluorocinnamoyl fluorosulfate; hydrolysis of the latter gives perfluorocinnamic acid.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2073–2076, September, 1989.