in further solvent(s) a pre-cooled (-7°C) soln. of XeF2 in 1,1,1,3,3-perfluorobutane added in three portions to a cold (-37°C) stirred soln. of trans-CF3CF=CFBF2 within 3 min; soln. stirred at -36 to -25°C for 3 h; not isolated; detected by (19)F-NMR;

in further solvent(s) a pre-cooled (-7°C) soln. of XeF2 in 1,1,1,3,3-perfluorobutane added in three portions to a cold (-37°C) stirred soln. of trans-CF3CF=CFBF2 within 3 min; soln. stirred at -36 to -25°C for 3 h; not isolated; detected by (19)F-NMR;