1: 76.8 percent / Al2O3, pyridinium chlorochromate (PCC) / CH2Cl2 / 0.5 h / Ambient temperature 2: 78.4 percent / diisopropylethylamine, 4-(dimethylamino)pyridine / CH2Cl2 / 3 h / 0 - 20 °C 3: 1.) sodium bis(trimethylsilyl)amide, hexamethylphosphoric triamide (HMPA) / 1.) THF, -78 deg C, 30 min, 2.) THF, 30 min 4: 89.3 percent / pyridine*(HF)x / tetrahydrofuran / 1 h / 0 °C 5: 28 percent / PPh3, diethyl azodicarboxylate (DEAD) / benzene / 48 h / Ambient temperature 6: 84 percent / tetrabutylammonium fluoride / tetrahydrofuran / 0.05 h / Ambient temperature 7: 49 percent / 3 N aq. HCl / tetrahydrofuran / 18 h / Ambient temperature View Scheme

<b>Multi-step reaction with 5 steps<br /> </b>1: 72.5 percent / 2 N aq. HCl / tetrahydrofuran / 24 h / Ambient temperature<br />2: 74.6 percent / camphorsulfonic acid / toluene / 4.5 h / Ambient temperature<br />3: 93 percent / imidazole, 4-(dimethylamino)pyridine / dimethylformamide / 14 h / Ambient temperature<br />4: 96.7 percent / LiAlH₄ / tetrahydrofuran; diethyl ether / 0.08 h / 0 &deg;C<br />5: 1.) tert-butyllithium, 2.) O₂ / 1.) THF, pentane, -78 deg C, 5 min<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: 74.6 percent / camphorsulfonic acid / toluene / 4.5 h / Ambient temperature<br />2: 93 percent / imidazole, 4-(dimethylamino)pyridine / dimethylformamide / 14 h / Ambient temperature<br />3: 96.7 percent / LiAlH₄ / tetrahydrofuran; diethyl ether / 0.08 h / 0 &deg;C<br />4: 1.) tert-butyllithium, 2.) O₂ / 1.) THF, pentane, -78 deg C, 5 min<br /> <br /> &nbsp;

<b>Multi-step reaction with 5 steps<br /> </b>2: CSA / toluene<br />3: imidazole, DMAP / dimethylformamide<br />4: LiAlH₄ / tetrahydrofuran / 0 &deg;C<br />5: 1.) t-BuLi, 2.) O₂ / 1.) THF, -78 deg C<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: CSA / toluene<br />2: imidazole, DMAP / dimethylformamide<br />3: LiAlH₄ / tetrahydrofuran / 0 &deg;C<br />4: 1.) t-BuLi, 2.) O₂ / 1.) THF, -78 deg C<br /> <br /> &nbsp;

<b>With</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '3587204', constants.ctx, '0')">tert.-butyl lithium</a>;&nbsp;<a href="#" onclick="return RXDsubstances(event, this, '3587218', constants.ctx, '0')">oxygen</a> <br />&nbsp;1.) THF, pentane, -78 deg C, 5 min;&nbsp;&nbsp;Yield given. Multistep reaction;&nbsp;<br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: imidazole, DMAP / dimethylformamide<br />2: LiAlH₄ / tetrahydrofuran / 0 &deg;C<br />3: 1.) t-BuLi, 2.) O₂ / 1.) THF, -78 deg C<br /> <br /> &nbsp;