1: 64 percent / aq. HCl / tetrahydrofuran / 0.5 h / 40 °C 3: 24 percent / electrochemical oxidation View Scheme

1: 54 percent / Ac2O / 48 h / Ambient temperature 2: 82 percent / aq. NaOH / CH2Cl2; methanol / 1 h / Ambient temperature 3: 1.) NaH / 1.) THF, room temperature - 30 min, reflux - 15 min, 2.) THF, room temperature, 20 h 4: 100 percent / aq. NaOH / 24 h / Heating 5: ceric ammonium sulfate 6: NH3 View Scheme