boron trifluoride diethyl etherate in dichloromethane T=20°C; 2 h;

borane-THF in tetrahydrofuran T=20°C; Reduction; 8 h;

2,2,6,6-tetramethyl-piperidine-N-oxyl; disodium hydrogenphosphate; potassium dihydrogenphosphate; sodium hypochlorite; sodium chlorite in acetonitrile T=45°C; 12 h;