1: With trimethylsilyl trifluoromethanesulfonate; triethylamine in toluene T=100°C; 5 h; 2: With 1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo-[2.2.2]octane bis(tetrafluoroborate) in N,N-dimethyl-formamide T=20°C; 1 h; Inert atmosphere; 3: With tetrabutyl ammonium fluoride in N,N-dimethyl-formamide 0.25 h;

water; hydrogen cation; N-fluoropyridinium trifluoromethanesulfonate 1.) CH2Cl2, reflux, 1 h; Yield given. Multistep reaction;

(i) LDA, toluene, (ii) FClO3, THF, (iii) aq. HCl, EtOH; Multistep reaction;