1: p-toluenesulfonic acid / dioxane; H2O / 3 h / Heating 2: 83 percent / pyridine / CH2Cl2 / 6 h / Ambient temperature 3: 28percent NaOH, H2O / 2 h / 10 °C 4: 83.4 percent / 18 h 5: Na-amalgam (5percent), methanol / 1 h / Ambient temperature View Scheme

1: p-toluenesulfonic acid / dioxane; H2O / 3 h / Heating 2: pyridine / CH2Cl2 / 6 h / Ambient temperature 3: 28percent NaOH, H2O / 2 h / 10 °C View Scheme

1: p-toluenesulfonic acid / dioxane; H2O / 3 h / Heating 2: 83 percent / pyridine / CH2Cl2 / 6 h / Ambient temperature 3: 28percent NaOH, H2O / 2 h / 10 °C View Scheme