1: 91 percent / DMAP / CH2Cl2 / 18 h / 0 - 5 °C 2: 80 percent / NaBH4 / dimethylsulfoxide / 2 h / 85 °C 3: 93 percent / NaIO4, AcOH / H2O View Scheme

<b>Multi-step reaction with 2 steps<br /> </b>1: 97 percent / PPTS / CH₂Cl₂ / Ambient temperature<br />2: 99 percent / n-Bu₄NF / tetrahydrofuran / Ambient temperature<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: NaI, CaCO₃ / tetrahydrofuran<br />2: 1.) Mg / 1.) Et₂O, 1 h, 2.) Et₂O, 30 min<br />3: 97 percent / PPTS / CH₂Cl₂ / Ambient temperature<br />4: 99 percent / n-Bu₄NF / tetrahydrofuran / Ambient temperature<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: 68 percent / toluene / 39 h / 0 - 3 &deg;C<br />2: 1.) Mg / 1.) Et₂O, 1 h, 2.) Et₂O, 30 min<br />3: 97 percent / PPTS / CH₂Cl₂ / Ambient temperature<br />4: 99 percent / n-Bu₄NF / tetrahydrofuran / Ambient temperature<br /> <br /> &nbsp;