1: 70 percent / CBr4; Ph3P / benzene / 3 h 2: 65 percent / Na2S / aq. ethanol / 4 h / 20 °C 3: 70 percent / Oxone / CH2Cl2 / 50 °C 4: 70 percent / KOH-Al2O3; CBr2F2 / CH2Cl2 View Scheme

lithium aluminium tetrahydride in ethylene glycol dimethyl ether 16 h; Heating;