1: 5percent H2SO4 / Heating 2: 100 percent / tetrahydrofuran / -78 °C 3: 80 percent / t-BuOK / 1,2-dimethoxy-ethane / 12 h / 50 °C 4: t-BuOK / dimethylformamide / 25 °C 5: SeO2/SiO2, t-BuOOH, AcOH / 110 °C 6: 10percent aq. H2SO4 / Heating 7: NaBH4, CeCl3 / ethanol / 1.) 0 deg C, 20 min, 2.) 45 deg C, 30 min 8: 60percent H2SO4 / ethanol / 5 h / 115 °C View Scheme

1: 5percent H2SO4 / Heating 2: 100 percent / tetrahydrofuran / -78 °C 3: t-BuOK / 1,2-dimethoxy-ethane / 12 h / 50 °C 4: t-BuOK / dimethylformamide / 25 °C 5: SeO2/SiO2, t-BuOOH, AcOH / 110 °C 6: 10percent aq. H2SO4 / Heating 7: NaBH4, CeCl3 / ethanol / 1.) 0 deg C, 20 min, 2.) 45 deg C, 30 min 8: 60percent H2SO4 / ethanol / 5 h / 115 °C View Scheme

1: 89 percent / H2SO4 / 16 h / Heating 2: 1.) n-BuLi / 1.) THF, hexane, -78 deg C, 30 min, 2.) THF, hexane, -78 deg C, 1 h 3: t-BuOK / 1,2-dimethoxy-ethane; toluene / 5 h / 25 °C 4: TiCl4, Et3N / CH2Cl2 / 1 h / 25 °C 5: benzene / 12 h / 25 °C 6: 79 percent / Et3N / toluene / 4 h / -10 °C 7: 1.) HBr, 2.) K2CO3 / 1.) CF3CH2OH, 80 deg C, 24 h, 2.) CF3CH2OH, 25 deg C, 1 h View Scheme