1: 80 percent / NBS / CH2Cl2 / 2 h / -40 °C 2: 72 percent / n-Bu3SnCl, NaCNBH3 / azobisisobutyronitrile / 2-methyl-propan-2-ol / 3 h / Heating 3: 75 percent / p-toluenesulfonic acid / benzene / 8 h / Ambient temperature View Scheme