Fluonnated, preparation from reaction with hydrogen

Mixtures of anhydrous hydrogen fluoride and tetrahydrofuran are successfully used as fluonnating agents to convert 1,1,2-trifluoro-l-alken-3-ols, easily prepared from bromotrifluoroethene via lithiation followed by the reaction with aldehydes or ketones, to 1,1, l,2-tetrafluoro-2-alkenes The yields are optimal with a 5 1 ratio of hydrogen fluoride to tetrahydrofuran The fluonnation reaction involves a fluoride ion-induced rearrangement (SN2 mechanism) of allylic alcohols [65] (equation 40)... 

Rearrangement of fluorine with concomitant nng opening takes place m fluonnated epoxides Hexafluoroacetone can be prepared easily from perfluo-ropropylene oxide by isomerization with a fluonnated catalyst like alumina pre treated with hydrogen fluoride [26, 27, 28] In ring-opening reactions of epoxides, the distribution of products, ketone versus acyl fluoride, depends on the catalyst [29] (equation 7) When cesium, potassium, or silver fluoride are used as catalysts, dimenc products also are formed [29]... 

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