Abstract: The invention relates to a process for the preparation of perfluorinated ethers of the formula (I)R--CF.sub.2 --CF.sub.3 (I)in which R is the radical CF.sub.3 (CF.sub.2).sub.2 --O--[CF(CF.sub.3)CF.sub.2 --O].sub.n --, in which n is an integer from 0 to 60, from compounds of the formula (II)R--[CF(CF.sub.3)CF.sub.2 --O--]CHF--CF.sub.3 (II)by heating these at 150.degree.-350.degree. C. in the presence of at least one of the compounds AlCl.sub.3, Albr.sub.3 or AlF.sub.3.

Abstract: A process for the preparation of perfluoropolyetheracyl fluorides of formula (I)F.sub.3 C(CF.sub.2).sub.2 --O--[CF(CF.sub.3)CF.sub.2 --O--].sub.n CF(CF.sub.3)COF (I)in which n is an integer from 0-60, wherein hexafluoropropylene oxide is oligomerized in the presence of CsF and a polyethylene glycol dimethyl ether and the reaction mixture thus formed is reacted with at least one of the halogen compounds HCl, HBr, BCl.sub.3, PCl.sub.3, SCl.sub.2 and R.sub.m SiCl.sub.4-m, where m=0, 1, 2 or 3 and R=C.sub.1 -C.sub.3 -alkyl or phenyl, dissolved in an aprotic solvent.

Abstract: The invention relates to a process for the preparation of perfluorinated ethers of the formula R--CF.sub.2 --CF.sub.3, in which R is the radical CF.sub.3 (CF.sub.2).sub.2 --O--[--CF(CF.sub.3)CF.sub.2 --O].sub.n --, in which n is an integer from 0 to 60, by decarbonylation of perfluoroether-acyl fluorides of the formula R--CF(CF.sub.3)--COF at 150.degree.-350.degree. C. in the presence of AlCl.sub.3 and/or AlBr.sub.3.

Abstract: The invention relates to a process for the preparation of fluorinated ethers of the formula (I)F.sub.3 C(CF.sub.2).sub.2 --O--CF(CF.sub.3)CF.sub.2 --O).sub.n CHFCF.sub.3 (I)where n is an integer from 10 to 60, from the compounds of the formula(II)F.sub.3 C(CF.sub.2).sub.2 --O--CF(CF.sub.3)CF.sub.2 --O).sub.n CF(CF.sub.3)COF (II)where n has the above meaning, by reaction with alkali metal hydroxide at temperatures of 90.degree. to 160.degree. C. and in the absence of solvents.