1.1: N,N-diisopropylamine; n-BuLi / tetrahydrofuran; hexane / 0.5 h / 0 °C 1.2: tetrahydrofuran; hexane / 16 h / 20 °C 2.1: 70 percent / tetrabutylammonium fluoride / tetrahydrofuran / 4 h / 20 °C 3.1: 60 percent / Ph3P; imidazole; iodine / tetrahydrofuran / 2 h / 20 °C View Scheme

<b>Multi-step reaction with 3 steps<br /> </b>1.1: BuLi / diethyl ether; hexane / 0.5 h / 20 &deg;C<br />1.2: diethyl ether; hexane / 16 h / 20 &deg;C<br />2.1: p-TsOH / dioxane; H₂O / 2 h / 50 &deg;C<br />3.1: imidazole / dimethylformamide / 2 h / 20 &deg;C<br /> <br /> &nbsp;