STEREOSELECTIVITY IN GLYCOSYLATION BY MEANS OF 2-AZIDO-2-DESOXY-D-GALACTOPYRANOSE DERIVATIVES AND THE SYNTHESIS OF THE DETERMINATIVE OLIGOSACCHARIDE OF BLOOD GROUP-A, TYPE-1
STEREOSELECTIVITY IN GLYCOSYLATION BY MEANS OF 2-AZIDO-2-DESOXY-D-GALACTOPYRANOSE DERIVATIVES AND THE SYNTHESIS OF THE DETERMINATIVE OLIGOSACCHARIDE OF BLOOD GROUP-A, TYPE-1
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DOI：
10.1007/bf00949960
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发表时间：
1982-01-01
期刊：
影响因子：
--
通讯作者：
KHORLIN, AY
中科院分区：
文献类型：
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作者：
BOVIN, NV;ZURABYAN, SE;KHORLIN, AY
α-氨基己糖键的形成仍然是α-糖苷合成中的一个难题。目前最有前途的合成α-己糖胺的方法是“叠氮法”[1]，该方法已被用来制备一系列具有2-乙酰胺-2-脱氧-α-D-糖基单元的杂低聚糖。 2-叠氮基-2-脱氧己糖起始糖基化衍生物的制备方法最近已得到显着简化[2-5]。在过去几年中，已经开发了两种从2-叠氮基-2-脱氧糖衍生物合成α-氨基糖苷的方法。第一种方法在于在Ag 2 CO 3 和AgClO 4 的混合物存在下通过2-叠氮基-2-脱氧-β-D-糖基氯例如(III)和(IV)[6]进行糖基化。该反应的空间选择性为85-90~[1, 7-11]。第二种方法需要使用2-叠氮基-2-脱氧-。 Helferieh糖基化条件下的顺式-D-糖基溴化物，例如 (V) 和 (Vi)[6] [12-14]。然而，没有给出选择更合适方法的标准。模型实验[2]表明，氯化物(IH)和溴化物(V)对苯甲醇和叔丁醇的糖基化缺乏空间选择性。最后，最近提出的在叠氮化物（VII）的情况下合成1, 2-顺式糖苷的“亚胺酯法”在糖在仲羟基上的糖基化方面并没有给出令人满意的结果[15]
Formation of the a-hexosaminide bond remains a difficult problem in the synthesis of a-glycosides. The most promising current method for the synthesis of a-hexosaminides is the" azide method"[1], which has been used to prepare a series of heterooligosaccharides with 2-aeetamide-2-desoxy-aD-glyeosyl units. The methods for preparation of the starting glycosylating derivatives of 2-azido-2-desoxyhexoses have recently been significantly simplified [2-5].Two methods have been developed in the past few years for the synthesis of a-glycosaminides from 2-azido-2-desoxy sugar derivatives. The first method lies in glycosylation by means of 2-azido-2-desoxy-~-D-glyeosyl chlorides such as (iII) and (IV)[6] in the presence of a mixture of Ag2CO 3 and AgC104. The steric selectivity of this reaction is 85-90~[1, 7-11]. The second method entails use of 2-azido-2-desoxy-. c~-D-glycosyl bromides such as (V) and (Vi)[6] under Helfferiehglycosylationeonditions [12-14]. However, criteria for selecting the more suitable method were not given. Model experiments [2] have shown the lack of steric selectivity in the glycosylation of benzyl alcohol and tert-butyl alcohol by chloride (IH) and bromide (V). Finally, the recently proposed" imidate method" for the synthesis of 1, 2-cis-glycosides in the case of azide (VII) does not give satisfactory results in the glyeosylation of sugars at secondary hydroxyl groups [15]