1.1: n-BuLi / tetrahydrofuran / -78 - 0 °C 1.2: I2 / benzene / 20 °C 2.1: 83 percent / KF; 18-crown-6 / dimethylformamide / 20 °C 3.1: CuI; NPrNH2 / Pd(PPh3)4 / benzene / 20 °C 4.1: pyridinium p-toluenesulfonate / methanol / 20 °C 5.1: aq. HCl / methanol / 0.25 h / 20 °C 6.1: 70 percent / Zn(Cu/Ag) / aq. methanol / 5 h / 40 °C View Scheme

<b>Multi-step reaction with 4 steps<br /> </b>1: 85 percent / LiBr / acetone; dimethylformamide / 3 h / Heating<br />2: 90 percent / BuLi, HMPA / hexane; tetrahydrofuran / 8 h<br />3: 90 percent / pyridine, H₂ / Lindlar cat. / hexane / 0 &deg;C<br />4: CrO₃, pyridine / CH₂Cl₂ / 0.5 h<br /> <br /> &nbsp;