1: NaBH4 / methanol / 2 h / Ambient temperature 2: 5percent HCl / tetrahydrofuran / 25 °C View Scheme

sodium tetrahydroborate in methanol 2 h; Ambient temperature;

1: 1.) -78 deg C, 5 min -> -20 deg C, 40 min 3: diisobutylaluminium hydride / toluene / -78 °C 5: pyridine / CH2Cl2 / 0.5 h / 0 °C 6: 57 percent / p-toluenesulphonic acid / methanol / Ambient temperature 7: pyridine / CH2Cl2 8: 93 percent / K2CO3 / methanol / 0.17 h / 0 °C 9: p-toluenesulfonic acid / CH2Cl2 10: 85 percent / KOH / H2O; ethanol / 2 h / 45 °C 11: 85 percent / chromic acid 12: 68 percent / acetic acid / H2O View Scheme