1.1: CeCl3; BuLi / tetrahydrofuran; hexane / 2.5 h / -50 °C 1.2: 85 percent / tetrahydrofuran; hexane / 3 h / -65 °C 2.1: ammonia / methanol / 24 h / 20 °C 3.1: 24.6 g / TBAF / tetrahydrofuran / 4 h / 20 °C View Scheme

<b>Multi-step reaction with 5 steps<br /> </b>1: 96 percent / dioxane; H₂O / 4 h / 90 &deg;C<br />2: 82 percent / pyridine / 18 h / 20 &deg;C<br />3: AgNO₃; pyridine / tetrahydrofuran / 3 h / 20 &deg;C<br />4: 78 percent / CrO₃; pyridine; Ac₂O / CH₂Cl₂ / 1 h / 15 &deg;C<br />5: 76 percent / p-TsOH / methanol; CHCl₃ / 0.08 h / 20 &deg;C<br /> <br /> &nbsp;