hydrogen; platinum(IV) oxide in 1,4-dioxane; ethanol P=760 Torr; 2 h;

trifluoroacetic acid in dichloromethane 3 h; Ambient temperature;

1: 11.5 percent / 1 N aq. H2SO4 / dioxane / 0.5 h / Irradiation 2: H2, acetic acid / PtO2 / dioxane / 760 Torr 3: 98 percent / pyridine / 1 h / 70 °C 4: 96.3 percent / H2SO4, conc. aq. HNO3 / 1 h 5: 82.3 percent / 20percent aq. H2SO4 / 2 h / Heating 6: 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / dioxane / 2 h / Heating 7: 96.2 percent / H2 / PtO2 / ethanol; dioxane / 2 h / 760 Torr View Scheme

1: 98 percent / pyridine / 1 h / 70 °C 2: 96.3 percent / H2SO4, conc. aq. HNO3 / 1 h 3: 82.3 percent / 20percent aq. H2SO4 / 2 h / Heating 4: 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / dioxane / 2 h / Heating 5: 96.2 percent / H2 / PtO2 / ethanol; dioxane / 2 h / 760 Torr View Scheme

1: 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / dioxane / 2 h / Heating 2: 96.2 percent / H2 / PtO2 / ethanol; dioxane / 2 h / 760 Torr View Scheme

1: H2, acetic acid / PtO2 / dioxane / 760 Torr 2: 98 percent / pyridine / 1 h / 70 °C 3: 96.3 percent / H2SO4, conc. aq. HNO3 / 1 h 4: 82.3 percent / 20percent aq. H2SO4 / 2 h / Heating 5: 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / dioxane / 2 h / Heating 6: 96.2 percent / H2 / PtO2 / ethanol; dioxane / 2 h / 760 Torr View Scheme

1: 78 percent / NaH, LiBr / 1,2-dimethoxy-ethane; dimethylformamide / 1.) 0 deg C, 10 min; r.t., 15 min, 2.) toluene, 70 deg C, 20 h 2: 58 percent / Me6Sn2 / benzene / 5 h / 70 °C / Irradiation 3: 87 percent / TFA / CH2Cl2 / 3 h / Ambient temperature View Scheme

1: 58 percent / Me6Sn2 / benzene / 5 h / 70 °C / Irradiation 2: 87 percent / TFA / CH2Cl2 / 3 h / Ambient temperature View Scheme

1: 73 percent / Me3SiCl, NaI / acetonitrile; H2O / 5 h / 65 °C 2: 78 percent / NaH, LiBr / 1,2-dimethoxy-ethane; dimethylformamide / 1.) 0 deg C, 10 min; r.t., 15 min, 2.) toluene, 70 deg C, 20 h 3: 58 percent / Me6Sn2 / benzene / 5 h / 70 °C / Irradiation 4: 87 percent / TFA / CH2Cl2 / 3 h / Ambient temperature View Scheme

1: 58 percent / Me6Sn2 / benzene / 5 h / 70 °C / Irradiation 2: 87 percent / TFA / CH2Cl2 / 3 h / Ambient temperature View Scheme