1: 89.5 percent / Et4NOTs, HOAc, t-BuOH / 1.) anodic oxidation (3.3 mA cm-1), room temperature, 2.) 1 d, room temperature 2: K2CO3 / dimethylformamide / 75 - 80 °C 3: 91.7 percent / 2N aq. NaOH / 3 h / Heating View Scheme

tetraethylammonium p-toluenesulfonate; acetic acid; tert-butyl alcohol 1.) anodic oxidation (3.3 mA cm-1), room temperature, 2.) 1 d, room temperature;