1: 57 percent / potassium t-butoxide / 2-methyl-propan-2-ol; tetrahydrofuran / 1 h / Ambient temperature 2: 96 percent / ceric ammonium nitrate / H2O; acetonitrile / 1 h / Ambient temperature 3: 73 percent / Na, NH3 liq. / tetrahydrofuran / 0.5 h / -78 °C View Scheme