1: 9.4 g / acetic acid; sodium azide / H2O / 18 h / 20 °C 2: 7.9 g / pyridine / CH2Cl2 / 24 h / 20 °C 3: 1.68 g / K10 Montmorillonite / benzene / 18 h / Heating 4: 112 mg / sodium methoxide; methanol / 18 h / 20 °C 5: 57 percent / p-TsOH / dimethylformamide / 1.5 h / 60 °C / 20 Torr View Scheme