1: 76 percent / diisobutylaluminum hydride / diethyl ether / 1 h / -20 °C 2: 83 percent / tetrahydrofuran / 1.) -15 deg C, 1 h, 2.) room temperature, 2 h 3: 93 percent / 46percent hydrogen fluoride / H2O; acetonitrile / 0.5 h / Ambient temperature View Scheme