n-butyllithium; Cu(I)[(CH3CN)4]BF4 1.) toluene, -78 deg C, 10 min, a) -78 deg C -> r.t., b) 75 deg C, 4 h; Multistep reaction;

1: 1.) n-butyllithium / 1.) hexane, THF, -78 deg C, 2.) THF, 1.5 h, -78 deg C 2: 1.) n-butyllithium, 2.) CuBF4*4CH3CN / 1.) toluene, -78 deg C, 10 min, a) -78 deg C -> r.t., b) 75 deg C, 4 h View Scheme

1: 1.) n-BuLi / 1.) THF, hexane, RT, 0.5 h, 2.) THF, hexane, reflux, 1 h 2: 1.) LDA / 1.) THF, -78 deg C, 1 h, 2.) THF, from -78 deg C to RT, 1 h 3: 92 percent / pyridine / CH2Cl2 / 12 h / Ambient temperature 4: 1 M BBr3 / 1.) CH2Cl2, -78 deg C, 1 h 2.) CH2Cl2, -78 deg C to RT, 1 h View Scheme