hydrogen bromide in acetic acid 5 h; Heating;

boron trifluoride diethyl etherate in toluene 4 h; Heating;

boron tribromide in chloroform 1. 10 min, dry ice; 2. 25 deg C;

sodium hydroxide; sodium dithionite in methanol Heating;

1: 46 percent / NaI / acetone / 31 h / Heating 2: 95 percent / zinc dust, sodium acetate / 5 h / Ambient temperature 3: 1.) chromium trioxide, conc. sulfuric acid, 2.) 6 N HCl / 1.) water, acetone, room temperature, 18 h, 2.) glacial acetic acid, 70 deg C, 30 min. View Scheme

1: 63 percent / Jones' reagent / acetone / 0.5 h / Ambient temperature 2: 95 percent / BBr3 / CHCl3 / 1. 10 min, dry ice; 2. 25 deg C View Scheme

chromium(VI) oxide; hydrogenchloride; sulfuric acid 1.) water, acetone, room temperature, 18 h, 2.) glacial acetic acid, 70 deg C, 30 min.; Yield given. Multistep reaction;

argentic oxide; nitric acid in water

1: 49 percent / isopentyl nitrite / dioxane / 0.5 h / 75 °C 2: 1.) 3,6-di(2'-pirydyl)-s-tetrazine,2.) pyridine / 1.) CHCl3, RT, 3 h, 2.) RT, 3 h 3: 1.) Zn, sodium acetate, 2.) acetic acid / 1.) reflux, 1 min, 2.) reflux, 1 min 4: 1.) ozone, 2.) Me2S / 1.) CH2Cl2, -78 deg C, 2.) CH2Cl2, from -78 deg C to RT 5: ethanol 6: K2Cr2O7 / 3 h / 110 °C 7: AcOH, 2percent aq. H2SO4 / 3 h / Heating 8: FeCl3, acetic acid / H2O / 72 h / Heating View Scheme

1: 1.) 3,6-di(2'-pirydyl)-s-tetrazine,2.) pyridine / 1.) CHCl3, RT, 3 h, 2.) RT, 3 h 2: 1.) Zn, sodium acetate, 2.) acetic acid / 1.) reflux, 1 min, 2.) reflux, 1 min 3: 1.) ozone, 2.) Me2S / 1.) CH2Cl2, -78 deg C, 2.) CH2Cl2, from -78 deg C to RT 4: ethanol 5: K2Cr2O7 / 3 h / 110 °C 6: AcOH, 2percent aq. H2SO4 / 3 h / Heating 7: FeCl3, acetic acid / H2O / 72 h / Heating View Scheme