methanol; boron trifluoride in dichloromethane 4 h; Ambient temperature;

1: pyridine / 10 h / 50 °C 2: 94 percent / NaH / tetrahydrofuran / Ambient temperature 3: 50 percent / boron trifluoride/methanol / CH2Cl2 / 4 h / Ambient temperature View Scheme

1: 94 percent / NaH / tetrahydrofuran / Ambient temperature 2: 50 percent / boron trifluoride/methanol / CH2Cl2 / 4 h / Ambient temperature View Scheme

1: 91 percent / pyridine; dimethylformamide / 2 h 2: pyridine / 10 h / 50 °C 3: 94 percent / NaH / tetrahydrofuran / Ambient temperature 4: 50 percent / boron trifluoride/methanol / CH2Cl2 / 4 h / Ambient temperature View Scheme