Реферат: 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.

Библиографическая ссылка: 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

Идентификаторы БД:

Web of science:	WOS:A1996VP24400003
Scopus:	2-s2.0-0030521175
OpenAlex:	W1994546046

Цитирование в БД:

БД	Цитирований
OpenAlex	39
Scopus	45
Web of science	39

Альметрики: