1: 95 percent / 49percent hydrobromic acid / CH2Cl2; H2O / 0 - 5 °C 2: 95 percent / acetone / 1 h / Heating 3: 72.5 percent / potassium carbonate / H2O / 0.5 h / Ambient temperature 4: 90 percent / pyridine / CHCl3 / 1 h / Heating View Scheme

1: 95 percent / 49percent hydrobromic acid / CH2Cl2; H2O / 0 - 5 °C 2: 95 percent / acetone / 1 h / Heating 3: 72.5 percent / potassium carbonate / H2O / 0.5 h / Ambient temperature 4: 95 percent / pyridine / CH2Cl2 / Heating View Scheme

1: 95 percent / 49percent hydrobromic acid / CH2Cl2; H2O / 0 - 5 °C 2: 95 percent / acetone / 1 h / Heating 3: 72.5 percent / potassium carbonate / H2O / 0.5 h / Ambient temperature 4: 90 percent / pyridine / CH2Cl2 / Heating View Scheme