1: CH2Cl2 / 1.) -30 deg C, 2.) room temperature, 4 h 2: 86 percent / potassium tert-butoxide / tetrahydrofuran / 4 h / Ambient temperature 3: 83 percent / iodine / benzene / 48 h / Heating View Scheme

1: CH2Cl2 / 1.) -30 deg C, 2.) room temperature, 4 h 2: 86 percent / potassium tert-butoxide / tetrahydrofuran / 4 h / Ambient temperature 3: 83 percent / iodine / benzene / 48 h / Heating 4: 79 percent / bromine, iron / CCl4 / 4 h View Scheme