1.1: MnO2 / CH2Cl2 / 0.25 h / 25 °C 1.2: 75 percent / LiAlH4 / tetrahydrofuran / 0.25 h / Heating 2.1: 86 percent / boron tribromide / CHCl3; CH2Cl2 / 0.25 h / 25 °C View Scheme

1: With manganese(IV) oxide in dichloromethane T=25°C; 0.25 h; 2: With lithium aluminium tetrahydride in tetrahydrofuran 0.25 h; Heating; Further stages.;