1: 95 percent / pyridinium chlorochromate / CH2Cl2 / 24 h / 25 °C 2: 78 percent / NH2OH*H2O, pyridine / ethanol / 1 h / Heating 3: 74 percent / LiAlH4 / tetrahydrofuran / 8 h / 80 - 85 °C 4: 5N HCl / 24 h / 25 °C View Scheme