1: 2,3-dibromopyridine With n-butyllithium in diethyl ether T=-78°C; 1 h; 2: With tri-isopropoxy-borane in diethyl ether T=-78 - 20°C; 3: 2,3-dimethylbutane-2,3-diol With acetic acid in diethyl ether T=20°C; 2 h;

1: 2-bromo-pyridine With lithium diisopropyl amide in diethyl ether T=-60°C; 0.75 h; 2: With tri-isopropoxy-borane in diethyl ether T=-60 - 20°C; 3: 2,3-dimethylbutane-2,3-diol With acetic acid in diethyl ether T=20°C; 2 h;

1.1: HBr 47 percent; NaNO2 1.2: CuBr 2.1: n-BuLi / diethyl ether / 1 h / -78 °C 2.2: B(Oi-Pr)3 / diethyl ether / -78 - 20 °C 2.3: 56 percent / glacial acetic acid / diethyl ether / 2 h / 20 °C View Scheme

1.1: HBr 47 percent; NaNO2 1.2: CuBr 2.1: Fe / acetic acid 3.1: HBr 47 percent; NaNO2 3.2: CuBr 4.1: n-BuLi / diethyl ether / 1 h / -78 °C 4.2: B(Oi-Pr)3 / diethyl ether / -78 - 20 °C 4.3: 56 percent / glacial acetic acid / diethyl ether / 2 h / 20 °C View Scheme

1.1: Fe / acetic acid 2.1: HBr 47 percent; NaNO2 2.2: CuBr 3.1: n-BuLi / diethyl ether / 1 h / -78 °C 3.2: B(Oi-Pr)3 / diethyl ether / -78 - 20 °C 3.3: 56 percent / glacial acetic acid / diethyl ether / 2 h / 20 °C View Scheme