1: tetrahydrofuran / 10 h / Inert atmosphere; Reflux 2: hydrogenchloride / dichloromethane; water / 5 h / Reflux View Scheme

1: tetrahydrofuran / 10 h / Inert atmosphere; Reflux 2: hydrogenchloride / dichloromethane; water / 5 h / Reflux 3: bromine; sodium carbonate / dichloromethane; water View Scheme

<b>Multi-step reaction with 4 steps<br /> </b>1: n-butyllithium / tetrahydrofuran / -78 - -40 &deg;C<br />2: tetrakis(triphenylphosphine) palladium⁽⁰⁾; potassium carbonate / tetrahydrofuran / 18 h / Reflux<br />3: pyridine; potassium permanganate / water / 24 h / Reflux<br />4: thionyl chloride / 5 h / Reflux<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: tetrabutylammomium bromide; palladium diacetate; potassium carbonate / water / 2 h / 70 &deg;C<br />2: pyridine; potassium permanganate / water / 24 h / Reflux<br />3: thionyl chloride / 5 h / Reflux<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: tetrakis(triphenylphosphine) palladium⁽⁰⁾; potassium carbonate / tetrahydrofuran / 18 h / Reflux<br />2: pyridine; potassium permanganate / water / 24 h / Reflux<br />3: thionyl chloride / 5 h / Reflux<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: tetrabutylammomium bromide; palladium diacetate; potassium carbonate / water / 2 h / 70 &deg;C<br />2: pyridine; potassium permanganate / water / 24 h / Reflux<br />3: thionyl chloride / 5 h / Reflux<br /> <br /> &nbsp;