1: CH2Cl2 / 0.33 h / Ambient temperature 2: DBN / CH2Cl2 / 6 h / Ambient temperature 3: K2CO3, MeOH / 5 h / Ambient temperature 4: 1N HCl / tetrahydrofuran / 12 h / Ambient temperature 5: 49 percent / pyridine / 12 h / -20 °C 6: 73 percent / PCC / CH2Cl2 / 2 h / Ambient temperature View Scheme

1: CH2Cl2 / 0.33 h / Ambient temperature 2: DBN / CH2Cl2 / 6 h / Ambient temperature 3: K2CO3, MeOH / 5 h / Ambient temperature 4: 1N HCl / tetrahydrofuran / 12 h / Ambient temperature 5: 49 percent / pyridine / 12 h / -20 °C View Scheme