1: 85 percent / aq. HCl / 24 h / Heating 2: acetyl chloride / acetone / 0.5 h / Ambient temperature 3: 1) NaH / 1) mineral oil, THF, 0 deg C, 3 min; 2) THF, 0 deg C, 20 min, r.t., 30 min 4: 49 percent / acetic acid; CH2Cl2 5: trifluoroacetic acid, water / 15 h / 55 °C View Scheme