1: 15-crown-5; sodium hexamethyldisilazane / tetrahydrofuran / -40 °C / Inert atmosphere 2: ammonium cerium (IV) nitrate / water; acetonitrile / 16 h / 20 °C / Inert atmosphere View Scheme

<b>Multi-step reaction with 3 steps<br /> </b>1.1: CoCl₂•6H₂O / ethanol / 0.5 h / 0 &deg;C / Inert atmosphere<br />1.2: 48 h / 20 &deg;C / Inert atmosphere<br />2.1: acetic acid / water / 12 h / 20 &deg;C / Inert atmosphere<br />3.1: magnesium sulfate / dichloromethane / 0.08 h / Inert atmosphere<br />3.2: 5 h / 20 &deg;C / Inert atmosphere<br /> <br /> &nbsp;

<b>Multi-step reaction with 2 steps<br /> </b>1.1: acetic acid / water / 12 h / 20 &deg;C / Inert atmosphere<br />2.1: magnesium sulfate / dichloromethane / 0.08 h / Inert atmosphere<br />2.2: 5 h / 20 &deg;C / Inert atmosphere<br /> <br /> &nbsp;

<b>Multi-step reaction with 5 steps<br /> </b>1.1: toluene-4-sulfonic acid / toluene / 3 h / Reflux; Inert atmosphere<br />2.1: palladium diacetate; N-ethyl-N,N-diisopropylamine; tris-(o-tolyl)phosphine / acetonitrile / 24 h / Reflux; Inert atmosphere<br />3.1: CoCl₂•6H₂O / ethanol / 0.5 h / 0 &deg;C / Inert atmosphere<br />3.2: 48 h / 20 &deg;C / Inert atmosphere<br />4.1: acetic acid / water / 12 h / 20 &deg;C / Inert atmosphere<br />5.1: magnesium sulfate / dichloromethane / 0.08 h / Inert atmosphere<br />5.2: 5 h / 20 &deg;C / Inert atmosphere<br /> <br /> &nbsp;