Synthesis of low molecular weight perfluoro oxymethylene vinyl ethers

Perfluoro oxymethylene vinyl ethers have been formed by a multi-step synthesis. The key intermediates are low molecular weight perfluoropolyether (PFPE) fluoroformates CF3O(CF2O)nCOF (I) n=1–6 obtained from the photo-oxidation of perfluoro propene (HFP) in perfluorohexane. Under certain conditions the light-mediated fluorination of PFPE fluoroformates (I) gives PFPE hypofluorites CF3O(CF2O)nCF2OF (II), which can be added to sym dichlorodifluoroethene to form the dichloro adduct CF3O(CF2O)nCF2OCFClCF2Cl (III) which, after dechlorination, gives the desired vinyl ethers CF3O(CF2O)nCF2OCFCF2 (IV). Every reaction step has to be properly controlled as far as the reaction variables are concerned. A mechanistic scheme is presented that is consistent with the observed experimental data.