Sherman A A, Yudina O N, Shashkov A S, Menshov V M, Nifant'ev N E
N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow.
Carbohydr Res. 2001 Feb 28;330(4):445-58. doi: 10.1016/s0008-6215(01)00002-7.
In order to prepare 3-aminopropyl glycosides of Neu5Ac-alpha-(2-->6')-lactosamine trisaccharide 1, and its N-glycolyl containing analogue Neu5Gc-alpha-(2-->6')-lactosamine 2, a series of lactosamine acceptors with two, three, and four free OH groups in the galactose residue was studied in glycosylations with a conventional sialyl donor phenyl [methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-2-thio-D-glycero-alpha- and beta-D-galacto-2-nonulopyranosid]onates (3) and a new donor phenyl [methyl 4,7,8,9-tetra-O-acetyl-5-(N-tert-butoxycarbonylacetamido)-3,5-dideoxy-2-thio-D-glycero-alpha- and beta-D-galacto-2-nonulopyranosid]onates (4), respectively. The lactosamine 4',6'-diol acceptor was found to be the most efficient in glycosylation with both 3 and 4, while imide-type donor 4 gave slightly higher yields with all acceptors, and isolation of the reaction products was more convenient. In the trisaccharides, obtained by glycosylation with donor 4, the 5-(N-tert-butoxycarbonylacetamido) moiety in the neuraminic acid could be efficiently transformed into the desired N-glycolyl fragment, indicating that such protected oligosaccharide derivatives are valuable precursors of sialo-oligosaccharides containing N-modified analogues of Neu5Ac.
为了制备Neu5Ac-α-(2→6')-乳糖胺三糖1的3-氨丙基糖苷及其含N-羟乙酰基的类似物Neu5Gc-α-(2→6')-乳糖胺2，研究了一系列在半乳糖残基中具有两个、三个和四个游离羟基的乳糖胺受体与传统唾液酸供体苯基[甲基5-乙酰氨基-4,7,8,9-四-O-乙酰基-3,5-二脱氧-2-硫代-D-甘油-α-和β-D-半乳-2-壬酮糖醛酸]酯（3）以及新供体苯基[甲基4,7,8,9-四-O-乙酰基-5-(N-叔丁氧羰基乙酰氨基)-3,5-二脱氧-2-硫代-D-甘油-α-和β-D-半乳-2-壬酮糖醛酸]酯（4）分别进行的糖基化反应。发现乳糖胺4',6'-二醇受体在与3和4的糖基化反应中效率最高，而酰亚胺型供体4与所有受体反应时产率略高，且反应产物的分离更方便。在用供体4进行糖基化反应得到的三糖中，神经氨酸中的5-(N-叔丁氧羰基乙酰氨基)部分可以有效地转化为所需的N-羟乙酰基片段，这表明此类保护的寡糖衍生物是含有Neu5Ac的N-修饰类似物的唾液酸寡糖的有价值前体。
