1: 99 percent / p-toluenesulfonic acid / 2 h / Ambient temperature 2: 99 percent / tetrabutylammonium fluoride / tetrahydrofuran / 3 h / Ambient temperature 3: 85 percent / sodium metaperiodate, water / diethyl ether / 3 h / Ambient temperature View Scheme

1: 99 percent / p-toluenesulfonic acid / 2 h / Ambient temperature 2: 99 percent / tetrabutylammonium fluoride / tetrahydrofuran / 3 h / Ambient temperature 3: 85 percent / sodium metaperiodate, water / diethyl ether / 3 h / Ambient temperature 4: 83 percent / sodium borohydride / methanol / 2 h / 0 °C View Scheme

1: 99 percent / p-toluenesulfonic acid / 2 h / Ambient temperature 2: 99 percent / tetrabutylammonium fluoride / tetrahydrofuran / 3 h / Ambient temperature 3: 85 percent / sodium metaperiodate, water / diethyl ether / 3 h / Ambient temperature 4: 1.) lithium 2,2,6,6-tetramethylpiperidine / 1.) THF, RT, 30 min, 2.) THF, 3 h View Scheme

<b>With</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '11343078', constants.ctx, '0')">sodium tetrahydroborate</a>;&nbsp;<a href="#" onclick="return RXDsubstances(event, this, '2231225', constants.ctx, '0')">diethyl methoxy borane</a>&nbsp;<b>in</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '102391', constants.ctx, '0')">tetrahydrofuran</a>;&nbsp;<a href="#" onclick="return RXDsubstances(event, this, '1098229', constants.ctx, '0')">methanol</a> <br />&nbsp;-78 deg C to RT, 12 h;&nbsp;<br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: 100 percent / imidazole / dimethylformamide / 12 h / 60 &deg;C<br />2: 74 percent / tetrahydrofuran / 16 h / -78 &deg;C<br />3: 60 percent / DIBAL / tetrahydrofuran; hexane / 4 h / -78 &deg;C<br />4: 1.) diethyl(methoxy)borane, 2.) sodium borohydride / 1.) THF, methanol, RT, 15 min, 2.) THF, methanol, a) -78 deg C, 4 h, b) from -78 deg C to RT, 8 h<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: 74 percent / NaH, n-BuLi / 20 h / -78 &deg;C<br />2: 60 percent / diisobutylaluminium hydride / tetrahydrofuran; hexane / 4 h / -78 &deg;C<br />3: 76 percent / Et₂BOMe, NaBH₄ / tetrahydrofuran; methanol / -78 deg C to RT, 12 h<br /> <br /> &nbsp;