copper(l) iodide in diethyl ether 2 h at 5 deg C, then 2 h at room temp.;

Yield given. Multistep reaction;

1: 95 percent / 5percent HCl / acetone / 6 h / Ambient temperature 2: 95 percent / diisobutylaluminum hydride / diethyl ether; toluene / 1.5 h / -10 °C 3: 85 percent / triphenylphosphine, Br2 / CCl4 / 16 h / Ambient temperature 4: 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 5: p-toluenesulfonic acid / methanol; H2O / 15 h / 20 °C View Scheme

1: 95 percent / 5percent HCl / acetone / 6 h / Ambient temperature 2: 95 percent / diisobutylaluminum hydride / diethyl ether; toluene / 1.5 h / -10 °C 3: 85 percent / triphenylphosphine, Br2 / CCl4 / 16 h / Ambient temperature 4: 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 5: p-toluenesulfonic acid / methanol; H2O / 15 h / 20 °C 6: 91 percent / pyridine / 24 h / Ambient temperature View Scheme

1: 95 percent / 5percent HCl / acetone / 6 h / Ambient temperature 2: 95 percent / diisobutylaluminum hydride / diethyl ether; toluene / 1.5 h / -10 °C View Scheme