81846-60-8Relevant articles and documents
Nitroalkene ring closure route to carbon-linked scaffolds for mimicking α-d-mannopyranosyl natural linkage
Baráth, Marek,Blahu?iaková, Alexandra,Jakub?inová, Jana,Ková?ová, Hana,Petru?, Ladislav,Petru?ová, Mária,Pribulová, Bo?ena
, (2020/06/02)
Abstract: Controlled treatment of 3,4,5,6,7-penta-O-acetyl-1,2-dideoxy-1-nitro-d-manno-hept-1-enitol with sodium methoxide in methanol was stopped by decationization at a point providing about equimolar mixture of α-d-mannopyranosyl and β-d-mannopyranosyl nitromethanes, from which the target α-anomer was isolated by chemisorption chromatography on a cation exchange resin in the Ba2+ form in a 36% yield. Direct reduction of the above mixture with ferrous hydroxide in situ to the corresponding amines, followed by the selective N-acetylation and the analogical chromatographic separation of both pertinent isomers with their stable ring structures gave N-acetyl-C-α-d-mannopyranosyl-methylamine. Alternative stopping of the initial ring forming reaction with acidified methanol at the above given product ratio initiated a subsequent Nef reaction and α-d-mannopyranosyl methanal dimethyl acetal was then chromatographically separated from its β-isomer on an anion exchange resin in the OH? form. Activations of two latter C-α-d-mannopyranosyl scaffolds by acid hydrolysis into respective reactive free amine or aldehyde forms were developed as well. Detailed reinvestigation of the classical method of preparation of d-mannosyl nitromethanes by thermal dehydration of a 1-deoxy-1-nitroalditol derived from d-mannose showed a maximum occurrence of only 18% of the required α-d-mannopyranosyl anomer. Graphic abstract: [Figure not available: see fulltext.].
3,4-Dipyranosyl-1,2,5-oxadiazole 2-oxides: Synthesis and X-ray structure
Baker, Kenneth W.J,March, Andrew R,Parsons, Simon,Paton, R.Michael,Stewart, Gavin W
, p. 8505 - 8513 (2007/10/03)
3,4-Di(2,3,4,6-tetra-O-acetyl-β-D-mannopyranosyl)-1,2,5-oxadiazole 2-oxide (7) has been synthesised from D-mannose by a route involving as the key step dimerisation of mannopyranosyl nitrile oxide 2. Three methods were used for the generation of the nitrile oxide: isocyanate-mediated dehydration of nitromethylmannose derivative 4, treatment of aldoxime 5 with aq. hypochlorite, and base-induced dehydrochlorination of hydroximoyl chloride 6. D-Gluco, D-galacto, D-xylo, and L-fucopyranosyl analogues 8-11 were prepared similarly. The structure of D-mannose-derived 1,2,5-oxadiazole 2-oxide 7 was established by X-ray crystallography.
Eine Zuckeraminosaeure als neuartiges Peptidmimetikum
Roedern, Erich Graf von,Kessler, Horst
, p. 684 - 686 (2007/10/02)
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