sulfuric acid in 1,4-dioxane 0.5 h; Irradiation;

di-tert-butyl peroxide; triisopropylsilanethiol

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 8: 1.) 20percent aq. H2SO4, aq. NaNO2, 2.) H2O / 1.) 0-5 deg C, 15 min, 2.) reflux, 1 h View Scheme

sulfuric acid in 1,4-dioxane 0.5 h; Irradiation;

sulfuric acid in 1,4-dioxane 0.5 h; Irradiation;

sulfuric acid in 1,4-dioxane 0.5 h; Irradiation;

sulfuric acid in 1,4-dioxane 0.5 h; Irradiation;

1: 22.5 percent / 1 N H2SO4 / dioxane / 0.5 h / Irradiation 2: 87.5 percent / methanol; dioxane; diethyl ether / 1 h / Ambient temperature View Scheme

sulfuric acid in 1,4-dioxane 0.5 h; Irradiation;

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 View Scheme