1: 71 percent / Ag2CO3 / tetrahydrofuran / 15 h / 20 °C 2: [Pd(PPh3)4]; CuBr / dioxane / 15 h / Heating 3: aq. HCl / diethyl ether / 15 h / 20 °C 4: 70 percent / aq. HBr / acetic acid / 5 h / Heating View Scheme

<b>Multi-step reaction with 2 steps<br /> </b>1.1: 70 percent / NaH / dimethylsulfoxide / 15 h / 0 - 20 &deg;C<br />2.1: 2,2,6,6-tetramethylpiperidine; BuLi / tetrahydrofuran; hexane / 1 h / -50 &deg;C<br />2.2: B(OMe)3 / tetrahydrofuran; hexane / 2 h / -75 &deg;C<br />2.3: 78 percent / aq. AcOH; AcOOH / tetrahydrofuran; hexane / -75 - 20 &deg;C<br /> <br /> &nbsp;