1: 1.) n-butyl-lithium, 3.) iodine 2: 94 percent / lithium aluminium hydride / diethyl ether / 12 h / Ambient temperature 3: 59 percent / oxalyl chloride, dimethyl sulphoxide / CH2Cl2 4: 5 percent / boron tri-iodide, ethylene / CH2Cl2 / -20 °C View Scheme

<b>Multi-step reaction with 5 steps<br /> </b>1: 58.5 percent / anhydrous potassium carbonate / butan-2-one / 192 h / Heating<br />2: potassium t-butoxide / toluene / 3 h / Heating<br />3: 84 percent / diethyl ether<br />4: 82 percent / N-bromosuccinimide, benzoyl peroxide / CCl₄ / 5 h / Heating<br />5: 82 percent / acetonitrile / 48 h / Ambient temperature<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: potassium t-butoxide / toluene / 3 h / Heating<br />2: 84 percent / diethyl ether<br />3: 82 percent / N-bromosuccinimide, benzoyl peroxide / CCl₄ / 5 h / Heating<br />4: 82 percent / acetonitrile / 48 h / Ambient temperature<br /> <br /> &nbsp;