1: With tert.-butyl lithium in tetrahydrofuran; pentane 0.833333 h; cooling; 2: With ethylene dibromide in tetrahydrofuran; pentane 0.5 h; cooling;

<b>Multi-step reaction with 3 steps<br /> </b>1.1: 78 percent / copper(I) oxide; pyridine / 12 h / Heating<br />2.1: 90 percent / HCl; iron / ethanol / 6 h / Heating<br />3.1: H₂SO₄; NaNO₂ / H₂O / 0.5 h / cooling<br />3.2: 72 percent / KI; copper / H₂O / 0.5 h / Heating<br /> <br /> &nbsp;