1: sodium, liquid ammonia / tetrahydrofuran / 0.5 h / -78 °C 2: 30 percent HBr / methanol; acetic acid / Heating 3: NaHCO3 / methanol; H2O / Ambient temperature 4: O2, NaHCO3 / platinum(IV) oxide / H2O / 48 h / Ambient temperature View Scheme