1: 91 percent / NaOH, 18-crown-6 2: 90 percent / TsOH 3: 81 percent / NaOH / ethanol View Scheme

1: 91 percent / NaOH, 18-crown-6 2: 90 percent / TsOH View Scheme

<b>Multi-step reaction with 2 steps<br /> </b>1: 1.) n-BuLi, S₈ <br />2: 100 percent / n-BuLi<br /> <br /> &nbsp;

<b>Multi-step reaction with 5 steps<br /> </b>1: 84 percent / Se, n-Bu-Li<br />2: 87 percent / H₂O₂ / pyridine<br />3: 51 percent<br />4: 88 percent / H⁽¹⁺⁾ <br />5: 100 percent / n-BuLi<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: 53 percent / Abrusov reaction<br />2: 1.) n-BuLi, S₈ <br />3: 100 percent / n-BuLi<br /> <br /> &nbsp;