1: 97 percent / NaOH (20percent aq.) / methanol / 3 h / Heating 2: 68 percent / trifluoroacetic anhydride / trifluoroacetic acid / 10 h / Ambient temperature 3: 84.5 percent / Na-borohydride / methanol / 2 h / Ambient temperature 4: 80.9 percent / 0.83 h / 190 - 200 °C / vacuo 5: 80 percent / H2 / Pd / acetic acid / 12 h / 760 Torr / Ambient temperature View Scheme