1.1: N-bromosuccinmide; dihydrogen peroxide / tetrachloromethane / 4 h / Reflux 2.1: magnesium / tetrahydrofuran / 2 h / Inert atmosphere 2.2: 4 h / Inert atmosphere 2.3: 4 h / Inert atmosphere 3.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 4 h / Inert atmosphere View Scheme

<b>Multi-step reaction with 2 steps<br /> </b>1: sodium tetrahydroborate / methanol / 0.5 h / Cooling with ice<br />2: 1H-imidazole / N,N-dimethyl-formamide / 10.25 h / 0 - 20 &deg;C / Inert atmosphere<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1.1: AlCl₃, aluminium chloride / dichloromethane / -10 &deg;C<br />1.2: 10 h / 5 - 20 &deg;C<br />2.1: potassium hydrogencarbonate / anhydrous xylene; water / 12 h / Reflux<br />3.1: sodium tetrahydroborate / methanol / 0.5 h / Cooling with ice<br />4.1: 1H-imidazole / N,N-dimethyl-formamide / 10.25 h / 0 - 20 &deg;C / Inert atmosphere<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: potassium hydrogencarbonate / anhydrous xylene; water / 12 h / Reflux<br />2: sodium tetrahydroborate / methanol / 0.5 h / Cooling with ice<br />3: 1H-imidazole / N,N-dimethyl-formamide / 10.25 h / 0 - 20 &deg;C / Inert atmosphere<br /> <br /> &nbsp;