The Development of new Methods for the Deoxygenation of Sugars

糖的脱氧在碳水化合物化学中占有重要地位。虽然有许多方法可以通过各种中间体进行脱氧，但对于糖化学中经常使用的乙酰化糖的脱氧，令人满意的方法的报道很少。然后，我们研究了将糖化合物转化为脱氧糖的新的有效途径。三苯基硅烷是将乙酰化糖转化为脱氧糖的良好脱氧试剂。脱氧有一个优点，即乙酰化糖可以在不影响缩醛等其他官能团的情况下脱氧，因为反应是在中性条件下进行的。对双（二苯基氢硅基）苯是一种很好的乙酰化糖脱氧还原剂，因为与三苯基硅烷相比，还原剂的用量更少，脱氧完全进行。此外，所得到的脱氧糖可以很容易地从反应混合物中分离出来，因为从试剂中得到的副产物是高沸点化合物。

Deoxygenation of sugars occupies a significant position in carbohydrate chemistry. Although there have been numerous methods for the deoxygenation via various intermediates, reports of satisfactory methods for the deoxygenation of acetylated sugars, which were often utilized in sugar chemistry, are rare. We have then investigated new efficient routes for the transformation of sugar compounds to deoxysugars.1. Triphenylsilane is a good deoxygenating reagent for the transformation of acetylated sugars to deoxysugars. The deoxygenation has a advantage that the acetylated sugars can be deoxygenated without affecting the other functinalities such as acetals, since the reaction proceeds under neutral conditions.2. p-bis(diphenylhydrosilyl)benzene is a excellent reducing reagent for the deoxygenation of acetylated sugars, since the deoxygenation proceeds completely with less amount of the reducing agent compared with the case of triphenylsilane. Furthermore, the resulting deoxysugars can be easily isolated from the reaction mixture, since the by-products derived from the reagent are high boiling compounds.