1: 92 percent / imidazole / dimethylformamide / 4 h / 60 °C 2: 84 percent / DIBAL-H / CH2Cl2; toluene / 0.33 h / -78 °C 3: 95 percent / sodium cyanoborohydride / ethanol / 4 h / Heating View Scheme

<b>Multi-step reaction with 3 steps<br /> </b>1.1: 90 percent / potassium carbonate / ethanol / 1 h / Heating<br />2.1: 94 percent / lithium chloride; triethylamine / tetrahydrofuran / 12 h / -78 - 20 &deg;C<br />3.1: TiCl₄; N,N-diisopropylethylamine / CH₂Cl₂ / 2 h / -78 &deg;C<br />3.2: 97 percent / CH₂Cl₂ / 2 h / -78 - 20 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 6 steps<br /> </b>1.1: 99 percent / thionyl chloride / 2 h / Heating<br />2.1: diethyl ether / 6 h / Heating<br />3.1: 69.3 g / pyridine / 12 h / 0 - 20 &deg;C<br />4.1: 90 percent / potassium carbonate / ethanol / 1 h / Heating<br />5.1: 94 percent / lithium chloride; triethylamine / tetrahydrofuran / 12 h / -78 - 20 &deg;C<br />6.1: TiCl₄; N,N-diisopropylethylamine / CH₂Cl₂ / 2 h / -78 &deg;C<br />6.2: 97 percent / CH₂Cl₂ / 2 h / -78 - 20 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 5 steps<br /> </b>1.1: diethyl ether / 6 h / Heating<br />2.1: 69.3 g / pyridine / 12 h / 0 - 20 &deg;C<br />3.1: 90 percent / potassium carbonate / ethanol / 1 h / Heating<br />4.1: 94 percent / lithium chloride; triethylamine / tetrahydrofuran / 12 h / -78 - 20 &deg;C<br />5.1: TiCl₄; N,N-diisopropylethylamine / CH₂Cl₂ / 2 h / -78 &deg;C<br />5.2: 97 percent / CH₂Cl₂ / 2 h / -78 - 20 &deg;C<br /> <br /> &nbsp;