1: 54 percent / TiCl4, Zn / tetrahydrofuran / 2 h / -10 °C 2: 75 percent / acetic anhydride, pyridine / 5 h / Heating 3: BBr3, methanol / CH2Cl2 / 3 h / Ambient temperature 4: pyridine View Scheme

1: BBr3, methanol / CH2Cl2 / 3 h / Ambient temperature 2: pyridine View Scheme

1: 75 percent / acetic anhydride, pyridine / 5 h / Heating 2: BBr3, methanol / CH2Cl2 / 3 h / Ambient temperature 3: pyridine View Scheme

pyridine Yield given;