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Ein schneller und robuster Zugang zu nativen (1→n) ‐ verknüpften C ‐ glycosidischen Disacchariden (n=2, 3, 4; links) wird beschrieben. Die Konfiguration des pseudoanomeren Kohlenstoffatoms kann hierbei vollständig kontrolliert werden. Auf einer noch kürzeren Route werden (1→n) ‐ verknüpfte 2 ‐ Desoxy ‐ C ‐ Glycoside (rechts) hoch diastereoselektiv erhalten. [ABSTRACT FROM AUTHOR]

Abstract: A series of novel spiro-isoxazoline C-disaccharides were synthesized by the key step of 1,3-dipolar cycloaddition reactions of exo-glycals and sugar nitrile oxides, and followed by catalytic debenzylation in the presence of Pd(OH)2/C. The cycloaddition reactions were carried out stereoselectively and afforded α-isomers exclusively except in the case of galactose. The biological activities of the novel disaccharides against the glycosidases (α-amylase, α-glucosidase, and β-glucosidase) and HIV and BVDV were evaluated. [Copyright &y& Elsevier]

Abstract: The synthesis of a C-disaccharide that is designed as a mimetic for the repeating unit disaccharide of hyaluronic acid is described. The target compound was obtained via the SmI2-promoted coupling reaction of the sulfone, 2-acetamido-4,6-O-benzylidene-3-O-tert-butyldimethylsilyl-1,2-dideoxy-1-pyridinylsulfonyl-β-d-glucopyranose (6), and the aldehyde, p-methoxyphenyl 2,3-di-O-benzyl-4-deoxy-4-C-formyl-6-O-p-methoxybenzyl-β-d-glucopyranoside (14). [Copyright &y& Elsevier]

Cross-metathesis (CM) of a variety of carbohydrate-based C-6 and olefins with related C-1 and C-6 carbohydrate-based olefins proved to be unselective. CM was selective when an unhindered straight chain olefin was coupled with a carbohydrate-based C-6 olefin. When related short chain alkenols were tethered, via a Me2Si linker, to a suitably protected carbohydrate-based C-6 olefin, good yields of ring-closed products were obtained with the second-generation Grubbs catalyst 3. A few examples where two carbohydrate-based olefinic alcohols were tethered via a Me2Si linker and subjected to ring-closing metathesis (RCM) have also been examined. [Copyright &y& Elsevier]

Intercellular communication is governed by interactions between surface oligosaccharides and glycoproteins. The biosynthesis of these molecules involves glycosidations catalyzed by glycosyltransferases and hydrolysis of O-glycosyl linkages catalyzed by glycosidases. Monosaccharide and disaccharide mimics such as carbasugars, iminosugars and C-linked disaccharides can be glycosidase or glycosyltransferase inhibitors. They are leads as new drugs to treat infective diseases and cancer. The preparation of a conduramine, a pentahydroxyindolizidine, and two C-linked disaccharides are outlined.