tetrabutyl ammonium fluoride in tetrahydrofuran 1.5 h; Ambient temperature;

Multi-step reaction with 6 steps 1: 1) lithium hexamethyldisilazide / 1) THF, -78 deg C, 1h, 2) room temperature, 30 min2: tetrahydrofuran / -78 °C3: DIBAL-H / toluene / 2 h / -78 °C4: 96 percent / pyridine, DMAP / CH2Cl2 / 2 h / 0 °C5: 1) hexamethyldisilazane (HMDS), ammonium sulfate, 2) trimethylsilyl triflate (TMSOTf) / 1) reflux, 2 h, 2) 1,2-dichloroethane, a) 5 deg C, 10 min, b) room temperature, 10 min6: 76 percent / 30percent aq. H2O2, pyridine / CH2Cl2 / 0.5 h / Ambient temperature  

Multi-step reaction with 4 steps 1: DIBAL-H / toluene / 2 h / -78 °C2: 96 percent / pyridine, DMAP / CH2Cl2 / 2 h / 0 °C3: 1) hexamethyldisilazane (HMDS), ammonium sulfate, 2) trimethylsilyl triflate (TMSOTf) / 1) reflux, 2 h, 2) 1,2-dichloroethane, a) 5 deg C, 10 min, b) room temperature, 10 min4: 76 percent / 30percent aq. H2O2, pyridine / CH2Cl2 / 0.5 h / Ambient temperature  

Multi-step reaction with 5 steps 1: diethylamine / tetrahydrofuran2: DIBAL / toluene / -78 °C3: pyridine / 0 °C4: 78 percent / trimethylsilyl triflate / 1,2-dichloro-ethane5: 10percent H2O2 / pyridine / CH2Cl2