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1 1999

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Hydroksyiminowe pochodne cukrów

Liberek Beata, Smiatacz Zygfryd

Wiadomości Chemiczne

1999

[Z] 53, 7-8

461-478

The article presents the methods of synthesis, properties and application of hydroxyimino derivatives of pyranoses and pyranosides. Sugar oximes possessing hydroxyimino group at first, second, third or fourth carbon atom of the pyranoid ring are well known. Here we focus on the 2-deoxy-2-hydroxyimino derivatives of saccharides, because of the interest they have received. It is due both to the ease in preparation of 2-hydroxyimino sugars and their utility as substrates in synthesis of many important mono- and oligasaccharides structures. The chemistry of the 2-deoxy-2hydroxyimino sugars was mostly investigated by R.U. Lemieux and F.W. Lichtenthaler. Lemieux et.al. worked out a general method of synthesis of 2-hydroxyimino-D-glycopyranosides, which was highly a-stereoselective (nitrosyl chloride method). The addition of nitrosyl chloride to an acetylated glycal led to the formation of a dimeric adduct of O-acetyl-2deoxy-2-nitrozo-a-D-glycopyranosyl chloride which reacted with the alcohol giving O-acetyl-2-deoxy-2-hydroxyimino-a-D-glycopyranoside. The derivatives of 2-deoxy-2-hydroxyimino glycosides were modified at C-2 to obtain 2-acetomido-2-deoxy-a-D-glycopyranosides and a-D-glycopyranosides respectively. (...) Lichtenthaler et.al. have elaborated a different methodology of the synthesis of the derivatives of sugars with 2-deoxy-2-hydroxyimino structure. It starts with the conversion of starting saccharide into its 2-hydroxyglycal ester, followed by the three-step sequence hydroxylaminolysis ŽbenzoylationŽphotobromination, which provides 2-deoxy-2-hydroxyimino-a-D-glycopyranosyl bromide, an useful synthetic intermediate in Koenings-Knorr type glycosylation.(...)