1: H2 / PtO2 2: KOH / tetrahydrofuran; methanol; H2O / 48 h / 25 °C View Scheme

<b>Multi-step reaction with 9 steps<br /> </b>2: diisobutylaluminium hydride<br />3: oxalic acid / tetrahydrofuran / Linde 4A molecular sieves<br />4: 82 percent / 1.) titanium tetrachloride, 2,4,6-trimethylpyridine, 2.) 1 M hydrochloric acid / CH₂Cl₂ / 1.) -78 degC, 5 min., 2.) -78 degC to r.t.<br />5: pyridinium chlorochromate / CH₂Cl₂ / 18 h / 25 &deg;C<br />6: 7.5 M KOH / tetrahydrofuran; methanol; H₂O / 48 h / 25 &deg;C<br />7: 96 percent / 10percent DMAP / pyridine / 3 h / 70 &deg;C<br />8: 89 percent / H₂ / Lindlar catalyst<br />9: 72 percent / BF₃*Et₂O<br /> <br /> &nbsp;

<b>Multi-step reaction with 6 steps<br /> </b>1: 82 percent / 1.) titanium tetrachloride, 2,4,6-trimethylpyridine, 2.) 1 M hydrochloric acid / CH₂Cl₂ / 1.) -78 degC, 5 min., 2.) -78 degC to r.t.<br />2: pyridinium chlorochromate / CH₂Cl₂ / 18 h / 25 &deg;C<br />3: 7.5 M KOH / tetrahydrofuran; methanol; H₂O / 48 h / 25 &deg;C<br />4: 96 percent / 10percent DMAP / pyridine / 3 h / 70 &deg;C<br />5: 89 percent / H₂ / Lindlar catalyst<br />6: 72 percent / BF₃*Et₂O<br /> <br /> &nbsp;

<b>Multi-step reaction with 5 steps<br /> </b>1: pyridinium chlorochromate / CH₂Cl₂ / 18 h / 25 &deg;C<br />2: 7.5 M KOH / tetrahydrofuran; methanol; H₂O / 48 h / 25 &deg;C<br />3: 96 percent / 10percent DMAP / pyridine / 3 h / 70 &deg;C<br />4: 89 percent / H₂ / Lindlar catalyst<br />5: 72 percent / BF₃*Et₂O<br /> <br /> &nbsp;