2,3,5-trimethyl-pyridine; dibromotriphenyl-phosphorane in dichloromethane 5 h; Ambient temperature;

1: 1.) AlCl3 2.)PCl5 / 1.) CS2, 0 deg C, 2.) phosphorus oxychloride, 40 to 45 deg C, 2.5 h 2: 93 percent / KOH / methanol; H2O / 0.17 h 3: 91 percent / lithium diisopropylamide / tetrahydrofuran / 1 h / Ambient temperature 4: 1.) n-butyllithium / 1.)THF, hexane, -78 degC 2.) room temperature, overnight 5: 80 percent / triphenylphosphine dibromide, collidine / CH2Cl2 / 5 h / Ambient temperature View Scheme

1: 91 percent / lithium diisopropylamide / tetrahydrofuran / 1 h / Ambient temperature 2: 1.) n-butyllithium / 1.)THF, hexane, -78 degC 2.) room temperature, overnight 3: 80 percent / triphenylphosphine dibromide, collidine / CH2Cl2 / 5 h / Ambient temperature View Scheme

1: 1.) n-butyllithium / 1.)THF, hexane, -78 degC 2.) room temperature, overnight 2: 80 percent / triphenylphosphine dibromide, collidine / CH2Cl2 / 5 h / Ambient temperature View Scheme

1: 93 percent / KOH / methanol; H2O / 0.17 h 2: 91 percent / lithium diisopropylamide / tetrahydrofuran / 1 h / Ambient temperature 3: 1.) n-butyllithium / 1.)THF, hexane, -78 degC 2.) room temperature, overnight 4: 80 percent / triphenylphosphine dibromide, collidine / CH2Cl2 / 5 h / Ambient temperature View Scheme