boron tribromide in dichloromethane T=-78 - 20°C; 3.5 h;

2: 64 percent / boron tribromide / CH2Cl2 / 3.5 h / -78 - 20 °C View Scheme

1: aq. ceric ammonium nitrate / acetonitrile; H2O / 0.75 h / Ambient temperature 2: copper acetate monohydrate, O2 / methanol / 2.5 h / Ambient temperature 3: 64 percent / boron tribromide / CH2Cl2 / 3.5 h / -78 - 20 °C View Scheme

1: 47 percent / 16 M aq. HNO3 / 0.25 h / Ambient temperature 3: 64 percent / boron tribromide / CH2Cl2 / 3.5 h / -78 - 20 °C View Scheme

1: copper acetate monohydrate, O2 / methanol / 2.5 h / Ambient temperature 2: 64 percent / boron tribromide / CH2Cl2 / 3.5 h / -78 - 20 °C View Scheme