Abstract Fluorosulfonyldifluoroacetyl fluoride (FOCCF 2 SO 2 F) quantitatively formed from sulfur trioxide and TFE through tetrafluoroethanesultone, has been converted into the octafluoro-5-iodo-3-oxapentanesulfonyl fluoride (ICF 2 CF 2 OCF 2 CF 2 SO 2 F) by the well known reaction involving MF, iodine and TFE in aprotic solvents. The iodo compound allowed us to obtain TFE telomers having both fluorosulfonyl and iodo terminal groups. ...
