The reaction of CF3O2 with haloalkanes (RX, XI, Br) in the presence of silver fluoride was studied as a means for preparing novel reactive polyfluoroalkoxysulfonyl fluorides. The following compounds have been prepared and characterized: ROCF2CF(CF3)SO2F, where R is CH2CHCH2, CF2CFCH2CH2, (CF3)2CFCH2CH2, CH3, CH2CBrCH2, SF5CH2CH2, CH2, FSO2CF(CF3)CF2OCH2. Infrared, mass and nmr spectra are presented