trifluoroacetic acid 0.5 h; Ambient temperature;

1: 70 percent / pyridine / tetrahydrofuran / 1) -78 deg C, 2) warm to RT, 3) reflux, 10 h 2: 1) n-butyllithium / 1) hexane, THF, -78 deg C, 2a) THF, -78 deg C, 2 h, 2b) warm to RT 3: 95 percent / trifluororacetic acid / 0.5 h / Ambient temperature View Scheme

1: 1) n-butyllithium / 1) hexane, THF, -78 deg C, 2a) THF, -78 deg C, 2 h, 2b) warm to RT 2: 95 percent / trifluororacetic acid / 0.5 h / Ambient temperature View Scheme

1: 1) NaH / 1) DME, 2h, RT, 2) 0.5 h 2: NaBH4 / H2O; ethanol / 2 h / Ambient temperature View Scheme