It is an object of the present invention is to provide a method of preparing 4-deoxy-D-mannose from widely available raw material selectively in a high yield. The method of the present invention comprises reducing a carbonyl group of the 2-position of levoglucosenone to convert to a hydroxyl group, adding an iodo-group to a double bond at the 4-position and an acyloxy group to the 3-position of levoglucosenone respectively, keeping a trans stereochemical relationship, forming a 1,6-anyhydro-4-deoxy-β-D-mannopyranose derivative having a deoxy from at the 4-position as the result of radical reduction of an iodo-group. The present invention make it possible to prepare a hard-obtaining rare sugar 4-deoxy-D-mannose in a high yield from starting levoglucosenone through a fewer processes than that of a convenient method including a reduction of a carbonyl group of levoglucosenone, an stereoselective addition reaction of an iodo-group and an acyloxy group to a double bond. Owning to this method, 4-deoxy-D-mannose used as not only a constitutional unit of useful sugar compounds including a sugar chain but also as a synthetic raw material can be readily supplied.
本发明的目的是提供一种从可广泛获得的原料中选择性地高产制备 4-脱氧-D-甘露 糖的方法。本发明的方法包括将左旋葡烯酮 2 位的羰基还原转化为羟基,在左旋葡烯酮 4 位的双键上加入
碘基,在 3 位上加入酰氧基,保持反式立体
化学关系,形成 1,6-任意氢-4-脱氧-β-
D-甘露糖衍
生物,该衍
生物具有 4 位上的脱氧,是
碘基自由基还原的结果。本发明使从起始左旋葡烯酮制备难得的稀有
糖类 4-脱氧-
D-甘露糖成为可能,与包括左旋葡烯酮的羰基还原、
碘基和酰氧基与双键的立体选择性加成反应的简便方法相比,本发明的制备过程更少。采用这种方法,不仅可以将 4-脱氧-
D-甘露糖用作有用的糖化合物(包括糖链)的组成单位,还可以将其用作合成原料。