1: With lithium diisopropyl amide in tetrahydrofuran T=-78°C; 1 h; Inert atmosphere; 2: With 1,2-dibromo-1,1,2,2-tetrafluoroethane in tetrahydrofuran T=20°C; 3 h; Inert atmosphere;

acetic acid 0.1 h; Microwave irradiationneat (no solvent);