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A Double Regio‐ and Stereoselective Glycosylation Strategy for the Synthesis of N‐Glycans
Author(s) -
Unverzagt Carlo,
Eller Steffen,
Mezzato Stefano,
Schuberth Ralf
Publication year - 2008
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200701251
Subject(s) - chemistry , stereoselectivity , chitobiose , glycan , glycosylation , trisaccharide , glycoconjugate , moiety , stereochemistry , diol , acetal , disaccharide , glycoprotein , biochemistry , organic chemistry , catalysis , chitin , chitosan
A building block approach for biantennary N‐linked oligosaccharides from glycoproteins (N‐glycans) has been developed. Starting from a core trisaccharide (β‐mannosyl chitobiose) containing a benzylidene‐protected β‐mannoside, the attachment of the disaccharide building blocks for the antennae can be performed in a double regio‐ and stereoselective manner. A short synthesis of a GlcNPhtβ1,2Man donor was developed. The benzylidene acetal moiety, as a minimal protection of the β‐mannoside, allows selective α‐glycosylation at OH‐3 of the 2,3‐diol with GlcNβ1,2Man trichloroacetimidate donors. Subsequent debenzylidenation leads to a 4,6‐diol, which can be selectively extended at OH‐6. Overreaction at OH‐4 was generally low when phthalimido‐protected donors were used. This general strategy represents a modular synthesis of N‐glycans and their glycoconjugates.