Perfluorinated trioxides

Olefinic betaines, e.g. 345, are formed from alkynes and the dimethylsulphide-sulphur trioxide complex . The surprising formation of the ketene 347 on heating the perfluorinated acetylene 346 with sulphur trioxide has been reported. ... 

A method for conversion of 38 into monosulfone 51 by oxidation with chromium trioxide in nitric acid was first claimed by Carboni and Kauer. Controlled oxidation of 38 affords a range of 1,3-dithietane 5-oxides and sulfones (Scheme 2.24). The perfluorinated dithietane 5-oxides are extremely thermally stable compounds. They completely decompose into smaller fragments only at about 500°C. 

A fluorinated heterocycle, 3,3,4,4-tetrafluoro-l,2-oxathietane-2,2-dioxide more commonly called tetralluoroethylene sultone (XXVll), is the starting material for the synthesis of Nalion perfluorinated ion exchange resins. This compound was synthesized independently at DuPont and the Russian Academy of Sciences by the reaction of tetralluoroethylene and sulfur trioxide (Eq 13.24). 

Cycloadditions The perfluorinated oxiran 70 reacts with sulfur trioxide at 150 °C to give the [3+2] cycloadduct 71... 

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