1: HCl / Ambient temperature 2: DBU / CH2Cl2 / Ambient temperature View Scheme

<b>Multi-step reaction with 3 steps<br /> </b>1: 72 percent / ethanol / 24 h / Ambient temperature<br />2: 75 percent / acetic acid / 24 h / Heating<br />3: 61 percent / n-BuLi / tetrahydrofuran; hexane / 1.) -78 deg C, 1 h, 2.) -78 deg C to r.t., overnight<br /> <br /> &nbsp;