Diastereoselective Synthesis of Aryl
<i>C</i>
‐Glycosides from Glycosyl Esters via C−O Bond Homolysis
作者:Yongliang Wei、Benjamin Ben‐zvi、Tianning Diao
DOI:10.1002/anie.202014991
日期:2021.4.19
O‐ and N‐glycoside analogues. C‐aryl glycosides are extensively investigated as drug candidates and applied to chemical biology studies. Previously, C‐aryl glycosides were derived from lactones, glycals, glycosyl stannanes, and halides, via methods displaying various limitations with respect to the scope, functional‐group compatibility, and practicality. Challenges remain in the synthesis of C‐aryl
相对于O-和N-糖苷类似物, C-芳基糖基化合物具有更好的体内稳定性。C-芳基糖苷作为候选药物被广泛研究并应用于化学生物学研究。此前,C-芳基糖苷是从内酯、糖醛、糖基锡烷和卤化物衍生而来,其方法在范围、官能团兼容性和实用性方面存在各种局限性。从容易获得的碳水化合物前体合成C-芳基核苷和 2-脱氧糖仍然存在挑战。在此,我们报道了一种从糖基酯和溴芳烃制备C-芳基和杂芳基糖苷(包括核苷和2-脱氧糖)的交叉偶联方法。碳水化合物底物的激活利用二氢吡啶 (DHP) 作为激活基团,然后通过 CO 键均裂脱羧生成糖基自由基。该策略代表了一种激活醇作为交叉偶联伙伴的新方法。糖基酯的方便制备及其稳定性证明了该方法在药物化学中的潜力。
Intramolecular 1,3-dipolar nitrone and nitrile oxide cycloaddition of 2- and 4-O-allyl and propargyl glucose derivatives: a versatile approach to chiral cyclic ether fused isoxazolidines, isoxazolines and isoxazoles
作者:Subir Ghorai、Ranjan Mukhopadhyay、Asish P. Kundu、Anup Bhattacharjya
DOI:10.1016/j.tet.2005.01.119
日期:2005.3
demonstrated the preferred formation of a five-memberedring to that of six or seven-membered rings. The nitrile oxide generated from a 3,4,5,6,7-pentaallyloxy-1-nitroheptane derivative obtained from pentaallylglucose underwent diastereoselective cycloaddition to give an isoxazoline fused to a pyran ring. Enantiopure isoxazoles containing tetrahydrofuran and oxepane rings were also prepared in good
Diastereoselective Synthesis of Novel Iminosugar-Containing UDP-Gal<i>f </i>Mimics: Potential Inhibitors of UDP-Gal Mutase and UDP-Gal<i>f</i> Transferases
作者:Virginie Liautard、Alphert E. Christina、Valérie Desvergnes、Olivier R. Martin
DOI:10.1021/jo061130e
日期:2006.9.1
diphosphono-β-Galf mimics based on an iminosugar skeleton linked to UMP by a 2-hydroxypropyl tether. The synthesis is based on the highly regio- and stereoselective cycloaddition of an original uridin-5‘-yl allylphosphonate with a 1,4-dideoxy-1,4-iminogalactitol-derived cyclic nitrone, followed by the reductive elaboration of the cycloaddition product. The resulting iminogalactose−UMP conjugates are novel sugar
thiophenols or alkanethiols with acetylglycosyl halides . 24 Acetylated alkyl l-thio-D-glucopyranosides can be obtained by reaction of 2,3,4,6-tetra-O-ace@-1-thio-/3-n-glucopyranose with alkyl bromides or iodides Z. In order to prepare 1-thioglycosides with non-participating groups, these compounds were deacylated and subsequently alkylated, usually with benzyl halides. The trichloroacetimidate method has been