1: 80 percent / tBuOK / 1,2-dimethoxy-ethane / 12 h / 50 °C 2: 100 percent / tBuOK / dimethylsulfoxide / 0.5 h / Ambient temperature 3: 1.) 5percent SeO2 on SiO2, aq. tBuOOH, 2.) aq. H2SO4 / 1.) AcOH, 110 deg C, 1 h, 2.) 110 deg C, 1 h 4: NaBH4, CeCl3*7H2O / ethanol / 0.33 h / 0 - 20 °C 5: 0.5 h / 45 °C 6: 309 mg / H2SO4 / ethanol / 5 h / 115 °C View Scheme

1: tBuOK / 1,2-dimethoxy-ethane / 12 h / 50 °C 2: tBuOK / dimethylsulfoxide / 0.5 h / Ambient temperature 3: 1.) 5percent SeO2 on SiO2, aq. tBuOOH, 2.) aq. H2SO4 / 1.) AcOH, 110 deg C, 1 h, 2.) 110 deg C, 1 h 4: 1.) NaBH4, CeCl3*7H2O / 1.) EtOH, 0 deg C -> room temperature, 20 min, 2.) 45 deg C, 30 min 5: H2SO4 / ethanol / 5 h / 115 °C View Scheme

1: t-BuOK / 1,2-dimethoxy-ethane; toluene / 5 h / 25 °C 2: TiCl4, Et3N / CH2Cl2 / 1 h / 25 °C 3: benzene / 12 h / 25 °C 4: 79 percent / Et3N / toluene / 4 h / -10 °C 5: 1.) HBr, 2.) K2CO3 / 1.) CF3CH2OH, 80 deg C, 24 h, 2.) CF3CH2OH, 25 deg C, 1 h View Scheme