1: CuCl / tetrahydrofuran / Heating 2: p-TsOH / methanol / Ambient temperature 3: 83 percent / HBr, H2SO4 / 4 h / Heating View Scheme

1: Li2CuCl4 / tetrahydrofuran 2: Ph3P*Br2 / CH2Cl2 View Scheme

1: 1.) Mg; 2.) p-TsOH / 1.) Li2CuCl4 / 1.) 2 h, ether, room t.; 2.) methanol, water, 1 h, reflux 2: 89 percent / 48percent HBr / 3 h / Heating 3: 55 percent / potassium tert-butoxide / benzene; dimethylsulfoxide / 0.17 h / 60 - 70 °C View Scheme

1: 1) Mg, 2) 0.1 M Li2CuCl4 / 1) THF, 2) below 5 deg C, 3 h; rt 2: p-toluenesulphonic acid / methanol / 4 h / Heating 3: 85 percent / PPh3Br2, pyridine / CH2Cl2; CCl4 / Ambient temperature 4: 1) Mg / 1) THF, 2) -70 deg C to room temperature, 2 h 5: 82 percent / m-chloroperbenzoic acid / CH2Cl2 / 0 - 5 °C 6: 64 percent / H5IO6 / tetrahydrofuran; diethyl ether / 2 h / 0 - 5 °C 7: 1) Mg / 1) THF, 2) 2 h, 0 deg C; room temperature View Scheme

sodium iodide in acetone 20 h; Heating;

Multi-step reaction with 2 steps 1: 1.) Mg; 2.) p-TsOH / 1.) Li2CuCl4 / 1.) 2 h, ether, room t.; 2.) methanol, water, 1 h, reflux2: 89 percent / 48percent HBr / 3 h / Heating  

Multi-step reaction with 2 steps 1: 1) Mg, 2) 0.1 M Li2CuCl4 / 1) THF, 2) below 5 deg C, 3 h; rt2: p-toluenesulphonic acid / methanol / 4 h / Heating  

 in  dimethyl sulfoxide T=20°C; 2 h;  Show Experimental Procedure