1: 88 percent / BF3*OEt2 / CH2Cl2 / 8 h / -80 °C 2: pyridine / 3 h / Ambient temperature 3: dicyclohexane-18-crown-6, KMnO4 / CH2Cl2 / 1) 15 deg C, 3 h, 2) room temp., 3 h 4: pyridine / 5 h / Ambient temperature 5: DIBALH / CH2Cl2 / 5 h / -80 °C 6: citric acid / methanol / 3 h / Ambient temperature 7: pyridine, DMAP / 5 h / Ambient temperature View Scheme

1: pyridine / 3 h / Ambient temperature 2: dicyclohexane-18-crown-6, KMnO4 / CH2Cl2 / 1) 15 deg C, 3 h, 2) room temp., 3 h 3: pyridine / 5 h / Ambient temperature 4: DIBALH / CH2Cl2 / 5 h / -80 °C 5: citric acid / methanol / 3 h / Ambient temperature 6: pyridine, DMAP / 5 h / Ambient temperature View Scheme

1: dicyclohexane-18-crown-6, KMnO4 / CH2Cl2 / 1) 15 deg C, 3 h, 2) room temp., 3 h 2: pyridine / 5 h / Ambient temperature 3: DIBALH / CH2Cl2 / 5 h / -80 °C 4: citric acid / methanol / 3 h / Ambient temperature 5: pyridine, DMAP / 5 h / Ambient temperature View Scheme

1: pyridine / 5 h / Ambient temperature 2: DIBALH / CH2Cl2 / 5 h / -80 °C 3: citric acid / methanol / 3 h / Ambient temperature 4: pyridine, DMAP / 5 h / Ambient temperature View Scheme

1: citric acid / methanol / 3 h / Ambient temperature 2: pyridine, DMAP / 5 h / Ambient temperature View Scheme

pyridine; 4-(N,N-dimethlyamino)pyridine 2 h; Ambient temperature;