- Affinity labelling at the 4-hydroxyl group of N- acetylglucosamine and N-acetylgalactosamine
-
Derivatives of N-acetylgalactosamine and N-acetylglucosamine in which the 4-OH group could be selectively labelled have been prepared from a common precursor.
- Moule, Christie J.,Clements, Peter R.,Hopwood, John J.,Crisp, Geoffrey T.
-
p. 1489 - 1501
(2007/10/03)
-
- 1,3,4,6-Tetra-O-acetyl-2-chloroacetamido-2-deoxy-β-D-glucopyranose as a glycosyl donor in syntheses of oligosaccharides
-
1,3,4,6-Tetra-O-acetyl-2-chloroacetamido-2-deoxy-β-D-glucopyranose was tested as a glycosyl donor for oligosaccharide synthesis via ferric chloride-catalyzed coupling reaction.Glycosyl acceptors tried (6 in all) were O-benzyl-protected D-galactosides having free OH groups at positions 3 and 4, respectively, and similarly protected glycosides of D-glucose and 2-acetamido-2-deoxy-D-glucose unsubstituted on O-4.Existing syntheses of all the acceptors were improved, in four instances by exploitation of Garegg and Hultberg's cyanoborohydride procedure for the conversion 4,6-O-benzylidene -> 6-O-benzyl .Good to excellent yields of β-linked disaccharides were obtained from the galactoside and glucoside acceptors, but with allyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-α-D-glucopyranoside, stereoselectivity was lost (α:β-ratio 1:2).Allyl and benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-β-D-glucopyranosides gave, respectively, the allyl and benzyl β-glycosides of the donor as major products.A mechanism is proposed for this transglycosidation reaction.The N-chloroacetyl groups in the disaccharide products were readily converted into N-acetyl by reduction with zinc-acetic acid.
- Dasgupta, Falguni,Anderson, Laurens
-
p. 239 - 255
(2007/10/02)
-
- O-BENZYLATED OXAZOLINE DERIVATIVES OF 2-ACETAMIDO-2-DEOXY-D-GLUCOPYRANOSE FROM 1-PROPENYL GLYCOSIDES. SYNTHESIS OF THE PROPENYL GLYCOSIDES AND THEIR DIRECT CYCLIZATION
-
1-Propenyl 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α- and -β-D-glucopyranosides (3α, 3β) were obtained by the successive isomerization and acetylation of the known allyl glycosides 1α and 1β.The allyl glycosides were also converted, via their benzylidene 4
- Nashed, Mina A.,Slife, Charles W.,Kiso, Makoto,Anderson, Laurens
-
p. 237 - 252
(2007/10/02)
-