1: 1.) NaH / 1.) DMSO, 1 h, 2.) 110 deg C, 16 h 2: 4-(dimethylamino)pyridine / acetonitrile / 1 h / Ambient temperature 3: n-tributyltin hydride, 2,2'-azobis(2-methylpropionitrile) (AIBN) / toluene / 2.5 h / 100 °C 4: AcOH / methanol / 1 h / 100 °C View Scheme

1: 4-(dimethylamino)pyridine / acetonitrile / 1 h / Ambient temperature 2: n-tributyltin hydride, 2,2'-azobis(2-methylpropionitrile) (AIBN) / toluene / 2.5 h / 100 °C 3: AcOH / methanol / 1 h / 100 °C View Scheme