1: 95 percent / diisobutylaluminum hydride / diethyl ether; toluene / 1.5 h / -10 °C 2: 85 percent / triphenylphosphine, Br2 / CCl4 / 16 h / Ambient temperature 3: 1.) cuprous iodide, 2,2' bipyridyl / 1.) THF, 2 deg C, 10 min, 2.) THF, a) 2 deg C, 2 h, b) RT, 15 h 4: p-toluenesulfonic acid / methanol; H2O / 15 h / 20 °C View Scheme

1: 95 percent / diisobutylaluminum hydride / diethyl ether; toluene / 1.5 h / -10 °C 2: 85 percent / triphenylphosphine, Br2 / CCl4 / 16 h / Ambient temperature 3: 1.) cuprous iodide, 2,2' bipyridyl / 1.) THF, 2 deg C, 10 min, 2.) THF, a) 2 deg C, 2 h, b) RT, 15 h 4: p-toluenesulfonic acid / methanol; H2O / 15 h / 20 °C 5: 91 percent / pyridine / 24 h / Ambient temperature View Scheme

diisobutylaluminium hydride in diethyl ether; toluene T=-10°C; 1.5 h;

Multi-step reaction with 2 steps 1: 81 percent / LiAlH4 / diethyl ether2: 83 percent / pyridinium chlorochromate / CH2Cl2 / 2 h