1: 87 percent / H2SO4 2: 38 percent / acetic acid; tetrahydrofuran / 168 h / 20 °C 3: Et3N / CH2Cl2 / 3 h / 20 °C 4: NaCl / dimethylformamide / 0.08 h / Heating 5: conc. HCl / 1 h / 80 °C 6: Et3N / acetone / 0.25 h / 0 °C 7: 1.) NaN3, 2.) 8 M HCl / 1.) Me2CO, H2O, 0 deg, 30 min, 2.) reflux, 10 min 8: 74 percent / methanol / 24 h / 20 °C View Scheme