diisobutylaluminium hydride in tetrahydrofuran; dichloromethane T=0 - 20°C; Inert atmosphere;

borane-THF T=0°C; 2 h;

1: 1.) NaNO2, aq. HCl, 2.) KI / 1.) 0 deg C, 20 min, 2.) H2O, RT, overnight 2: 97 percent / BH3*THF / 2 h / 0 °C View Scheme

1.1: bromine; acetic acid / 16 °C / Inert atmosphere 2.1: hydrogenchloride; sodium hydroxide; sodium nitrite / water / 2 h / 0 °C / Inert atmosphere 2.2: 0.83 h / 35 - 90 °C / Inert atmosphere 3.1: sulfuric acid / Reflux; Inert atmosphere 4.1: diisobutylaluminium hydride / tetrahydrofuran; dichloromethane / 0 - 20 °C / Inert atmosphere 4.2: 0 °C / Inert atmosphere View Scheme

PPh3.Br2 in acetonitrile T=5 - 20°C;

dipyridinium dichromate in dichloromethane T=20°C; 4 h; Inert atmosphere;

1.1: CBr4; PPH3 / CH2Cl2 / 0 °C 2.1: n-BuLi; i-Pr2NH / hexane; tetrahydrofuran / 1 h / -78 °C 2.2: 48 percent / tetrahydrofuran; hexane / -78 - 20 °C 3.1: 3 percent / PPh3; Et3N / Pd(OAc)2 / dimethylformamide; H2O / 15 h / 130 °C View Scheme