1: 81 percent / pyridine / 24 h / 0 °C 2: 95 percent / LiBr / 1,2-dimethoxy-ethane / 15 h / 50 °C 3: 1.) Mg, 1,2-dibromomethane, 2.) CuI, pyrrolidine / 1.) Et2O, 2.5 h, 2.) Et2O, 15 min, room temperature, 3.) Et2O, -90 deg C, 3 h 4: 95 percent / DIBAH / diethyl ether; hexane / 2 h / Ambient temperature View Scheme