1: With 2,2,6,6-tetramethyl-1-piperidinyloxy, free radical; sodium hydrogencarbonate; potassium bromide in dichloromethane T=-5°C; 0.5 h; 2: With sodium hypochlorite in dichloromethane; water 3: With hydrogenchloride; sodium sulfite in dichloromethane; water Product distribution / selectivity;