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Journal articles
Regioselective Galactofuranosylation for the Synthesis of Disaccharide Patterns Found in Pathogenic Microorganisms
Abstract : Koenigs-Knorr glycosylation of acceptors with more than one free hydroxyl group by 2,3,5,6-tetrabenzoyl galactofuranosyl bromide was performed using diphenylborinic acid 2-aminoethyl ester (DPBA) as inducer of regioselectivity. High regioselectivity for the glycosylation on the equatorial hydroxyl group of the acceptor was obtained thanks to the transient formation of a borinate adduct of the corresponding 1,2-cis diol. Nevertheless formation of orthoester byproducts hampered the efficiency of the method. Interestingly electron-withdrawing groups on O-6 or on C-1 of the acceptor displaced the reaction in favor of the desired galactofuranosyl containing disaccharide. The best yield was obtained for the furanosylation of p-nitrophenyl 6-O-acetyl mannopyranoside. Precursors of other disaccharides, found in the glycocalix of some pathogens, were synthesized according to the same protocol with yields ranging from 45 to 86%. This is a good alternative for the synthesis of biologically relevant glycoconjugates.
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01578548
Contributor : Laurent Jonchère <>
Submitted on : Wednesday, September 13, 2017 - 1:53:06 PM
Last modification on : Tuesday, January 12, 2021 - 4:49:26 PM
Long-term archiving on: : Thursday, December 14, 2017 - 1:39:58 PM
Contributor : Laurent Jonchère <>
Submitted on : Wednesday, September 13, 2017 - 1:53:06 PM
Last modification on : Tuesday, January 12, 2021 - 4:49:26 PM
Long-term archiving on: : Thursday, December 14, 2017 - 1:39:58 PM