in dichloromethane cooled down solution of (n-C4F9SO2)2O to -15°C, then stirring for 2 days at room temp.;

in ethylene glycol dimethyl ether the Na salt of the ketone is prepared in the react. mixture from NaH and the corresponding ketone, at 0°C C4F9SO2F is added, stirring 1 h, refluxed at 50-60°C, 15 h;

sodium carbonate in dichloromethane