phosphorus tribromide in dichloromethane T=20°C; 1 h;

1H-imidazole in dichloromethane 1.5 h; Inert atmosphereCooling with ice;

borane-THF in tetrahydrofuran T=0 - 20°C; 1 h;

diisobutylaluminium hydride in tetrahydrofuran T=20°C;

1: 95 percent / K2CO3 / acetone / Heating 2: 83 percent / 85 percent KOH / methanol; tetrahydrofuran / 6 h / Heating 3: 90 percent / BH3*(CH3)2S / tetrahydrofuran / 0 - 60 °C View Scheme

1.1: sulfuric acid / 22 h / 75 °C / |Inert atmosphere 2.1: sodium hydride / tetrahydrofuran; N,N-dimethyl-formamide / 0.67 h / |Inert atmosphere; |Cooling with ice 2.2: 2.83 h / |Inert atmosphere 3.1: potassium hydroxide; hydrogenchloride / water / 24 h / |Inert atmosphere 3.2: 0.67 h / |Inert atmosphere; |Cooling with ice View Scheme

manganese(IV) oxide in ethyl acetate 5 h; Heating;