tetra-(n-butyl)ammonium iodide; potassium carbonate in acetone 36 h; RefluxInert atmosphere;

1: 16.5 g / 6percent H2O2 2: 2 g / K2CO3 / dimethylformamide View Scheme

1: 1.) 15percent n-BuLi / 1.) ether, hexane, reflux, 3 h; 2.) reflux, 1 h 2: 900 mg / piperidine / pyridine 3: 320 mg / 2,3-dichloro-5,6-dicyanobenzoquinone 4: 180 mg / boron trichloride View Scheme