Simple one-pot regioselective 6-O-phosphorylation of carbohydrates and trehalose desymmetrization
作者:A. Abragam Joseph、Chun-Wei Chang、Cheng-Chung Wang
DOI:10.1039/c3cc47180b
日期:——
Biologically essential carbohydrate 6-phosphates, especially trehalose 6-phosphate, can be synthesized easily in excellent overall yields in 2 steps involving minimum protecting group manipulations. We can cleave the diphenylphosphate group for further synthetic objectives.
Selective C−O Bond Cleavage of Sugars with Hydrosilanes Catalyzed by Piers’ Borane Generated In Situ
作者:Jianbo Zhang、Sehoon Park、Sukbok Chang
DOI:10.1002/anie.201708109
日期:2017.10.23
[(C6F5)2BH], generated in situ, is demonstrated to promote the hydrosilylative reduction of sugars, providing a series of linear or cyclic polyols with high chemo- and regioselectivities undermildconditions. Studies of catalytic reactivity and regioselectivity with regard to the C−O bond cleavage with hydrosilanes suggest an importance of the steric environment around the anomeric carboncenter of the
Piers的硼烷[(C 6 F 5)2 BH]原位生成,可促进糖的氢化硅烷化还原,在温和条件下提供一系列具有高化学选择性和区域选择性的线性或环状多元醇。关于用氢硅烷裂解C-O键的催化反应性和区域选择性的研究表明,糖异头碳中心周围的空间环境很重要。
β‐Selective
<i>C</i>
‐Glycosylation and its Application in the Synthesis of Scleropentaside A
作者:G. Jacob Boehlich、Nina Schützenmeister
DOI:10.1002/anie.201900995
日期:2019.4
C‐Glycosides are carbohydrates that bear a C−C bond to an aglycon at the anomeric center. Due to their high stability towards chemical and enzymatic hydrolysis, these compounds are widely used as carbohydrate mimics in drug development. Herein, we report a general and exclusively β‐selective method for the synthesis of a naturally abundant acyl‐C‐glycosidic structural motif first found in the scleropentaside
A practical, facile method was developed for the preparation of 1,5-anhydroalditol via per-O-TMS-glycopyranosyl iodide with LiBH4. A series of 1,5-anhydroalditols were prepared in excellent yields (up to 92%) from unprotected carbohydrates within 2 days under mild conditions. In addition, multi-gram scale preparation of 1,5-anhydroglucitol (1,5-AG), a major polyol present in human serum, was developed
made out of a tripeptide of β‐D‐Galp‐(1→3)‐CH2‐α‐D‐GalNAc‐O‐Ser and conjugated with keyhole limpet hemocyanin (KLH) protein induced an early and strongimmuneresponse (IgG antibodies) in mice. Antigen 3 made out of an α‐C‐galactoside analogue did not induce such an immuneresponse (see scheme).
抗癌疫苗:抗原2由β-的三肽的出d -Gal p - (1→3)-CH 2 -α- d -GalNAc-O-Ser和与钥孔血蓝蛋白(KLH)缀合蛋白诱导的早期和小鼠具有很强的免疫反应(IgG抗体)。由α-C-半乳糖苷类似物制成的抗原3不会诱导此类免疫反应(请参阅方案)。