A method for preparing hexose derivatives comprises the steps of providing a silylated hexose, treating the silylated hexose with a first carbonyl compound in the presence of a catalyst to form an ketalized hexose, treating the ketalized hexose with a second carbonyl compound followed by treating with a first reductant to form an etherized hexose, and converting the etherized hexose into a target hexose derivative, which can be 2-alcohol hexose, 3-alcohol hexose, 4-alcohol hexose, or a 6-alcohol hexose. In particular, the present invention can prepare the hexose derivatives with highly regioselective scheme to protect individual hydroxyls of monosaccharide units and install an orthogonal protecting group pattern in a one-pot manner
Conformation-Controlled Hydrogen-Bond-Mediated Aglycone Delivery Method for α-Xylosylation
作者:Deqin Cai、Ya Bian、Shengjie Wu、Kan Ding
DOI:10.1021/acs.joc.1c00187
日期:2021.8.6
α-xyloside-containing molecules was full of challenges. Herein, a robust method is presented for selective α-xylosylation via combination of a rare conformation-controlled strategy and the hydrogen-bond-mediated aglycone delivery method. Various native branched α-xyloside structures necessitate an orthogonally protected xyloside, and a three-pot preparation method of the xylosyl donor was developed for this novel
α-木糖基化聚糖和木糖基衍生物是生物医学上重要的分子,它们显示出许多抗感染、癌症、炎症等生物活性。由于缺乏有效的α-木糖基化方法,含α-木糖苷分子的合成充满挑战。在此,通过结合罕见的构象控制策略和氢键介导的苷元递送方法,提出了一种用于选择性 α-木糖基化的稳健方法。各种天然支链 α-木糖苷结构需要正交保护的木糖苷,为此新的 α-木糖基化方法开发了木糖基供体的三锅制备方法,并进一步应用于木葡聚糖侧链 N 的首次合成。这项工作提供了一种有效的 α-木糖基化方法,可以实现各种 α-木糖苷结构。构象控制策略对五碳吡喃糖的化学也有重要参考。
One-Pot Synthesis of<i>N</i>-Acetyl- and<i>N</i>-Glycolylneuraminic Acid Capped Trisaccharides and Evaluation of Their Influenza A(H1 N1) Inhibition
作者:Yun Hsu、Hsiu-Hwa Ma、Larry S. Lico、Jia-Tsrong Jan、Koichi Fukase、Yosuke Uchinashi、Medel Manuel L. Zulueta、Shang-Cheng Hung
DOI:10.1002/anie.201309646
日期:2014.2.24
N‐acetylneuraminic acid (Neu5Ac) α(2→6)‐linked to galactose (Gal) as binding sites for influenza virus hemagglutinin. N‐Glycolylneuraminic acid (Neu5Gc) in place of Neu5Ac is known to affect hemagglutinin binding in other species. Not normally generated by humans, Neu5Gc may find its way to human cells from dietary sources. To compare their influence in influenza virus infection, six trisaccharides with Neu5Ac
The first total synthesis of a highly branched heptadecasaccharide moiety of the native bioactive galectin-3-targeting polysaccharide from Carthamus tinctorius has been accomplished via a photo-assisted convergent [6+4+7] one-pot coupling strategy. This work demonstrates a representative example to explore potential active domains of the polysaccharide for structure–activity relationship studies, thereby
Synthesis of the tetrasaccharide repeating unit of the O-antigen from E. coli O131 was accomplished through a linear strategy involving rationally protected monosaccharide units derived from commercially available sugars. The challenging α-glycosylation of N-acetyl neuraminicacid was achieved through activation of thioglycoside using NIS-mediated glycosylation strategy. The target tetrasaccharide