Homolytic addition of tetrahydrofuran at the vinylsulfonyl groups of 1,4-bis(vinylsulfonyl)tetra-fluorobenzene in the absence of radical initiator at 20 and 55degreesC leads to formation of 1,4-bis[2-(2-tetrahydrofuryl)ethylsulfonyl]tetrafluorobenzene in 16 and 42% yield, respectively, and a mixture of telomers. The latter are formed as a result of opening of the tetrahydrofuran ring in the adduct.