1: 2) aqueous sulphuric acid / 1) toluene-p-sulphonic acid / 1) a) temperature raised to 95 deg C, 4 h, b) 95 deg C, 4 h, 2) dioxane, 50 deg C, 2 h 2: 51 percent / oxygen / palladium chloride, copper(II) chloride / dimethylformamide; H2O / 70 °C / 1) 150 min, 2) 1 h 3: 87 percent / sodium hydroxide / methanol / 3 h / 15 °C View Scheme

1: 2) aqueous sulphuric acid / 1) toluene-p-sulphonic acid / 1) a) temperature raised to 95 deg C, 4 h, b) 95 deg C, 4 h, 2) dioxane, 50 deg C, 2 h 2: 4 percent / oxygen / palladium chloride, copper(II) chloride / dimethylformamide; H2O / 70 °C / 1) 150 min, 2) 1 h View Scheme

boron trifluoride diethyl etherate; dihydrogen peroxide in diethyl ether T=20°C; 1 h;