Selectin Receptors 4: Synthesis of Tetrasaccharides Sialyl Lewis A and Sialyl Lewis X Containing A Spacer Group1,2 Full article
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Journal of Carbohydrate Chemistry
ISSN: 0732-8303 , E-ISSN: 1532-2327 |
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| Output data | Year: 1996, Volume: 15, Number: 8, Pages: 939-953 Pages count : 15 DOI: 10.1080/07328309608005700 | ||||
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Abstract:
Synthesis of two isomeric tetrasaccharides, namely Neu5Acα(2→3)Galβ(1→3)[Fucα(1→4)GlcNAcβ (sLea) and Neu5Acα(2→3)Galβ(1→4)[Fucα(1→3)]GlcNAcβ (sLex) as 3-aminopropyl glycosides is described. Preparation of these compounds was performed by sialylation of selectively protected trisaccharides Lea and Lex which contain three unsubstituted OH groups at positions 2, 3 and 4 of Gal residue. Glycosylation of Lex trisaccharide with ethylthio sialoside under promotion by NIS and TfOH in acetonitrile was effective and regio- and stereoselective to give sLex derivative in 81% yield. In contrast, sialylation of the Lca acceptor was accompanied by a variety of undesirable by-processes, namely. N-thioethylation of the GlcNAc residue, β-sialylation, and lactonisation. In order to improve the yield of sLca tetrasaccharide the glycosylation of Lea acceptor by sialyl donors of ethyl and phenyl thioglycoside (promoted by NIS-TfOH or NBS-Bu4NBr), xanthate (promotion by NIS-TfOH mixture or MeOTf) and phosphite (promoted by TMSOTf) types was also studied. Among the reactions investigated the glycosylation by phenyl thioglycoside sialoside promoted by NIS-TfOH gives the best yield (39%) of sLea tetrasaccharide product.
Cite:
Nifant'ev N.E.
, Tsvetkov Y.E.
, Shashkov A.S.
, Kononov L.O.
, Menshov V.M.
, Tuzikov A.B.
, Bovin N.V.
Selectin Receptors 4: Synthesis of Tetrasaccharides Sialyl Lewis A and Sialyl Lewis X Containing A Spacer Group1,2
Journal of Carbohydrate Chemistry. 1996. V.15. N8. P.939-953. DOI: 10.1080/07328309608005700 WOS Scopus OpenAlex
Selectin Receptors 4: Synthesis of Tetrasaccharides Sialyl Lewis A and Sialyl Lewis X Containing A Spacer Group1,2
Journal of Carbohydrate Chemistry. 1996. V.15. N8. P.939-953. DOI: 10.1080/07328309608005700 WOS Scopus OpenAlex
Identifiers:
| Web of science: | WOS:A1996VP24400003 |
| Scopus: | 2-s2.0-0030521175 |
| OpenAlex: | W1994546046 |