tert.-butyl lithium in tetrahydrofuran; pentane -78 deg C to room temperature;

2,3,5-trimethyl-pyridine; PPh3.Br2 in dichloromethane T=21°C; 5 h;

1: 99 percent / pyridine / 1.) 0 degC, 15 min 2.) room temperature, 12 h 2: 68 percent / AlCl3 / CS2 / 0.5 h / Ambient temperature 3: 95 percent / PCl5 / POCl3 / 2 h / 45 - 50 °C 4: 92 percent / NaNH2 / tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 degC 2.) 50 degC, 2 h 5: 94 percent / P(C6H5)3*Br2, collidine / CH2Cl2 / 5 h / Ambient temperature View Scheme

1: 68 percent / AlCl3 / CS2 / 0.5 h / Ambient temperature 2: 95 percent / PCl5 / POCl3 / 2 h / 45 - 50 °C 3: 92 percent / NaNH2 / tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 degC 2.) 50 degC, 2 h 4: 94 percent / P(C6H5)3*Br2, collidine / CH2Cl2 / 5 h / Ambient temperature View Scheme

1: 95 percent / PCl5 / POCl3 / 2 h / 45 - 50 °C 2: 92 percent / NaNH2 / tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 degC 2.) 50 degC, 2 h 3: 94 percent / P(C6H5)3*Br2, collidine / CH2Cl2 / 5 h / Ambient temperature View Scheme

1: 92 percent / NaNH2 / tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 degC 2.) 50 degC, 2 h 2: 94 percent / P(C6H5)3*Br2, collidine / CH2Cl2 / 5 h / Ambient temperature View Scheme

potassium carbonate in methanol Inert atmosphere;

1: 1.) n-butyllithium, HMPA / 1.)THF, hexane, -78 degC to 0 degC 2.) 45-50 degC, 2 h 2: 63 percent / 5percent HCl / tetrahydrofuran; H2O / 2 h / 50 °C View Scheme

tert.-butyl lithium in tetrahydrofuran; pentane -78 deg C to room temperature;