TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The metal fluoride is cesium fluoride, potassium fluoride, rubidium fluoride, lithium fluoride, sodium fluoride, calcium fluoride, barium fluoride, magnesium fluoride, strontium fluoride or silver fluoride.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The converting step involves the thermal decomposition of fluorosulfate moiety of formula (-CF2-OSO2F) in the presence of metal fluoride catalysts. The process further comprises: reacting (III-A) and (III-B) with hexapropylene epoxide in the presence of a suitable catalyst, to obtain acyl fluoride compounds of formulae (R1f-O-CF2-CF2-CF2-O-CF(CF3)-C(=O)-F) (IV-A) and (IV-B); and pyrolyzing (IV-A) and (IV-B) to give fluorovinyl ether compounds of formulae (R1f-O-CF2-CF2-CF2-O-CF=CF2) (V-A) and (V-B). The pyrolysis of (V-A) and (V-B) is effected in gas phase by contacting the acyl fluorides with a catalyst, preferably sodium sulfate or sodium carbonate, at 150-350 degrees C. The process further comprises: reacting (III-A) and (III-B) with elemental fluorine and at least one olefin compound of formula (A1-C(A2)=C(A3)-A4) (A) in the liquid phase at -150 degrees C to 0 degrees C to give haloether compounds of formulae (R1f-O-CF2-CF2-CF2-O-CA1A2-CFA3A4) (VIA) and (VI-B); and reacting (III-A) and (III-B) with elemental fluorine in the presence of a fluoride catalyst to give hypofluorite compound of formulae (R1f-O-CF2-CF2-CF2-OF) (VIII-A) and (VIII-B). (VI-A) and (VI-B) are further reacted by dehalogenation/dehydrohalogenation for obtaining vinyl ether compounds of formulae (R1f-O-CF2-CF2-CF2-O-CA5=CFA6) (VII-A) and (VII-B). The process further comprises reacting (VIII-A) and (VIII-B) with (A) to give (VI-A) and (VI-B).A1-A6 = H, F, Cl or Br.Preferred Components: (A) is 1,2-dichloro-1,2-difluoroethylene, 1,2-dibromo-1,2-difluoroethylene or 1-chloro-1,2-difluoroethylene. SPECIFIC COMPOUNDS - Preparation of 2,2,3,3-tetrafluoro-3-trifluoromethoxy-propionyl fluoride of formula (CF3-O-CF2-CF2-C(=O)-F) (III-Aa) and 2,2,3,3-tetrafluoro-3-(1,1,2,2-tetrafluoro-2-fluorosulfonyl-ethoxy)-propionyl fluoride is disclosed as (III-A). Preparation of 2,2,4,5,5-pentafluoro-(1,3)dioxolane-4-carbonyl fluoride of formula (III-Bb) is disclosed as (III-B).    EXAMPLE - A flow of 1.2N l/hour of trifluoromethyl hypofluoride diluted with 2.4 N l/hour of nitrogen, was fed during 2 hours through an inlet connection in a glass reactor containing trichlorofluoromethane (40 g) and fluorosulfuric acid pentafluoroallyl ester (16 g), maintained at -50 degrees C to give fluorosulfuric acid 1,1,2,2,3,3-hexafluoro-3-trifluoromethoxy-propyl ester (1a). (1a) (10 g) and cesium fluoride (0.1 g) were added to a rector at -70 degrees C. The mixture was heated through an external bath and refluxed for 2 hours, under vigorous stirring to give 2,2,3,3-tetrafluoro-3-trifluoromethoxy-propionyl fluoride (6.8 g).