1: 4.28 g / BH3-Me2S / tetrahydrofuran 2: pyridine 3: 85 percent / Li2CuCl4 / tetrahydrofuran 5: 97 percent / p-TsOH*H2O / benzene 6: 1) i-Pr2NLi / 1) THF, -78 degC; 2) THF 7: 45 percent / TiCl2(Oi-Pr)2 / CH2Cl2 / 20 h / -78 - 25 °C View Scheme

Multi-step reaction with 7 steps 1: 4.28 g / BH3-Me2S / tetrahydrofuran2: pyridine3: 85 percent / Li2CuCl4 / tetrahydrofuran5: 97 percent / p-TsOH*H2O / benzene6: 1) i-Pr2NLi / 1) THF, -78 degC; 2) THF7: 24 percent / TiCl2(Oi-Pr)2 / CH2Cl2 / 20 h / -78 - 25 °C  

Multi-step reaction with 3 steps 1: 4.28 g / BH3-Me2S / tetrahydrofuran2: pyridine3: 85 percent / Li2CuCl4 / tetrahydrofuran  

Multi-step reaction with 2 steps 1: 4.28 g / BH3-Me2S / tetrahydrofuran2: pyridine  

Multi-step reaction with 5 steps 1: 4.28 g / BH3-Me2S / tetrahydrofuran2: pyridine3: 85 percent / Li2CuCl4 / tetrahydrofuran5: 97 percent / p-TsOH*H2O / benzene  

Multi-step reaction with 4 steps 1: 4.28 g / BH3-Me2S / tetrahydrofuran2: pyridine3: 85 percent / Li2CuCl4 / tetrahydrofuran