1: With lithium diisopropyl amide in tetrahydrofuran T=-80°C; 2: With 1,2-dibromo-1,1,2,2-tetrachloroethane in tetrahydrofuran T=-80 - 0°C; 1 h;

1: 56 percent / nickel peroxide / benzene / 15 h / Heating 2: 9 percent / 1) bromine, 2) triethylamine / benzene / 7 h / Heating View Scheme

1: 1) thionylchloride, 2) aqueous potassium hydroxide / 1) 0 deg C, 1 h, 2) reflux, 8 h. 2: 56 percent / nickel peroxide / benzene / 15 h / Heating 3: 9 percent / 1) bromine, 2) triethylamine / benzene / 7 h / Heating View Scheme

1: 77 percent / Heating 2: 1) thionylchloride, 2) aqueous potassium hydroxide / 1) 0 deg C, 1 h, 2) reflux, 8 h. 3: 56 percent / nickel peroxide / benzene / 15 h / Heating 4: 9 percent / 1) bromine, 2) triethylamine / benzene / 7 h / Heating View Scheme