1: p-toluenesulfonic acid / toluene / 12 h / 105 °C 2: TsOH / methanol / 24 h / 50 °C 3: diisobutylaluminum hydride / CH2Cl2 / 1 h / -78 °C 4: pyridine / 1 h / 0 - 20 °C 5: sodium azide / dimethylformamide / 24 h / 50 °C 6: p-toluenesulfonic acid / methanol / 24 h / 50 °C 7: H2 / Lindlar catalyst / methanol / 12 h / 23 °C / 760 Torr 8: acetonitrile / 4 h 9: benzyltrimethylammonium dichloroiodate / tetrahydrofuran / 1.75 h / 60 °C 10: acetonitrile / 40 h / 35 °C 11: aq. HCl / methanol / 16 h / 23 °C 12: H2O / 4 h / 95 °C View Scheme