1: DIBAL / toluene; CH2Cl2 / 0.5 h / -78 °C 2: BF3*Et2O / 2 h / -20 °C 3: imidazole / dimethylformamide / 0.17 h / 40 °C 4: 80percent m-chloroperbenzoic acid / CH2Cl2 / 1) -78 to 0 deg C, 30 min,2) 0 deg C,2 h 5: 1) n-butyllithium, 2) BF3*Et2O / 1) THF, hexane, -78 deg C, 5 min,2) THF, hexane, 10 min, 3) THF, hexane, -30 deg C, 2 h 6: pyridine / 15 h / Ambient temperature 7: 6percent sodium amalgam / tetrahydrofuran; methanol / 3 h / Ambient temperature 8: 77 percent / 0.3N hydrochloric acid / acetonitrile / 2 h 9: 1) t-BuOK / 1) THF, 2) THF, 30 min 10: tetrabutylammonium fluoride / tetrahydrofuran / 48 h View Scheme