Synthesis of allyl 2-O-(α-l-arabinofuranosyl)-6-O-(α-d-mannopyranosyl)-β-d-mannopyranoside, a unique plant N-glycan motif containing arabinose
摘要:
The synthesis of the trisaccharide allyl 2-O-(alpha -L-arabinofuranosyl)-6-O-(alpha -D-mannopyranosyl)-beta -D-mannopyranoside is reported. Stereoselective glycosylation at C-6 of a non-protected allyl beta -mannoside with the acetylated alpha -D-mannosyl bromide gave the alpha-(1 --> 6)-disaccharide as the main product and the crystalline 3,6-branched trisaccharide as minor compound. Further glycosylation of the 2,3 diol (1 --> 6) disaccharide with L-arabinofuranosyl bromide furnished a mixture of 3-O- and 2-O-alpha -L-Ara-trisaccharides from which the title compound was isolated. (C) 2000 Elsevier Science Ltd. All rights reserved.
Synthesis of Benzaldehyde-Functionalized Glycans: A Novel Approach Towards Glyco-SAMs as a Tool for Surface Plasmon Resonance Studies
作者:Sebastian Kopitzki、Knud J. Jensen、Joachim Thiem
DOI:10.1002/chem.200902693
日期:——
In recent years the interest in tools for investigating carbohydrate–protein (CPI) and carbohydrate‐carbohydrate interactions (CCI) has increased significantly. For the investigation of CPI and CCI, several techniques employing different linking methods are available. Surfaceplasmonresonance (SPR) imaging is a most appropriate tool for analyzing the formation of self‐assembled monolayers (SAM) of
anomeric activation of acetylated glycosyl iodides. This reactivity can be exploited for straightforward access to allyl glycosides unprotected at the O-2 position. The reported protocol appears to be convenient in comparison with the pre-existing ones in that shorter experimental times are needed and the use of strong acids is avoided. Suitable structural features of substrates (6-deoxy sugars or use
Dihydroxylation of allyl 2,3,4-tri-O-benzyl-6-O-tritylglycosides provides diols, the anomers of which can easily be separated by column chromatography in a practical scale. These anomers can be cleanly transformed into alpha- and beta-glycosyloxyacetic acids, respectively, via oxidative cleavage of the diol followed by oxidation.