1: aq. NaOH, NaBH4 / methanol / 0.5 h 2: 71 percent / 48percent HBr / acetic acid / 12 h / Heating 3: H2, aq. HCl / 10percent Pd/C / ethanol / 96 h / Ambient temperature 4: 55 percent / NaHCO3 / dimethylformamide / 4 h / Heating View Scheme