Oxazoline synthesis of 1,2-trans-2-acetamido-2-deoxyglycosides

Zurabyan, S. E.; Volosyuk, T. P.; Khorlin, A. Ya.

doi:10.1016/s0008-6215(00)82136-9

Cited by 71 publications

(18 citation statements)

References 22 publications

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“…The oxazoline method is an excellent glycosidation reaction of alcohols for achieving high stereoselectivity, in which the b-O-glycoside linkage could be exclusively formed by using certain acid catalysts [19][20][21][22] . In this article, CSA and TfOH were used as acid promoters for the reaction.…”

Section: Resultsmentioning

confidence: 99%

Chemical modification of hydroxyl groups of poly(vinyl alcohol) by a glycosidation reaction

Takasu

Niwa

Itou

et al. 2000

Macromol. Rapid Commun.

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A new procedure for chemical modification of poly(vinyl alcohol) (PVA) was established by a glycosidation reaction of hydroxyl groups in PVA with triacetylated sugar oxazoline 1. 1H and 13C NMR analyses indicated that triacetylated N‐acetyl‐D‐glucosamine (GlcNAc) was introduced onto a PVA backbone selectively via a β‐O‐glycoside linkage. Deacetylation of triacetylated GlcNAc‐substituted PVA 2 resulted in GlcNAc‐substituted PVA 3 in good yield. These modified PVAs 2 and 3 exhibited solubilities and thermal properties different from the original PVA.

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Section: Resultsmentioning

confidence: 99%

Chemical modification of hydroxyl groups of poly(vinyl alcohol) by a glycosidation reaction

Takasu

Niwa

Itou

et al. 2000

Macromol. Rapid Commun.

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“…T h e s y n t h e s i s o f s u g a r o x a z o l i n e d e r i v a t i v e s necessitates a tedious process such as conventional -protection/deprotection of hydroxyl groups (38)(39)(40)(41)(42)(43). The chemical approaches involve the careful design of protecting groups, catalysts and solvents.…”

Section: F One-pot Synthesis Of Oligosaccharides Through Direct Actimentioning

confidence: 99%

Design and Utilization of Chitinases with Low Hydrolytic Activities

Kohri¹,

Kobayashi²,

Shoda³

2007

TIGG

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Enzymatic glycosylation reactions by combined use of activated donor substrates and deactivated enzymes have been reviewed. Glycosidase-catalyzed transglycosylation reaction of sugar oxazolines to various glycosyl acceptors have successfully been achieved for the formation of polyand oligo-saccharides such as chitin, glycosaminoglycans, and the core trisaccharide of N-linked oligosaccharide. These reactions proceeded efficiently using appropriate glycosidases under basic conditions, where the enzymes showed lower hydrolytic activity toward their natural substrates. In order to realize the transglycosylation reactions under neutral conditions, several mutants chitinaseA1 from Bacillus circulans WL-12 were constructed. Some of mutants were found to be efficient for transglycosylation under neutral conditions. These reactions could be applied to the stepwise synthesis of oligosaccharides and oligosaccharide-containing macromonomers. Novel thermosensitive polymers carrying oligosaccharides have successfully been synthesized by the radical copolymerization of the resulting macromonomers with N-isopropylacrylamide. One-pot chemo-enzymatic synthesis of oligosaccharides starting from a free sugar has been demonstrated via a sugar oxazoline intermediate formed in situ and the subsequent enzymatic transglycosylation. This novel technique of transferring an oligosaccharide moiety having an N-acetylhexosamine unit is a promising tool to pave the way to the new generation of oligosaccharide synthesis.

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“…[2,15,16] The conversion of 4, which is accessible in high yields by Jeanloz' procedure, [17] into glycosides 3 is known as the oxazoline method. [18] It has the conceptual advantage that the natural 2-acetamido group is obtained directly in the glycosylation step. However, due to the low reactivity of 4, harsh reaction conditions are required, for example ptoluenesulfonic acid in refluxing nitromethane or tolu- [ ene, [3,18] leading to decomposition of 3 and 4 and, therefore, moderate yields.…”

Section: Introductionmentioning

confidence: 99%

“…[18] It has the conceptual advantage that the natural 2-acetamido group is obtained directly in the glycosylation step. However, due to the low reactivity of 4, harsh reaction conditions are required, for example ptoluenesulfonic acid in refluxing nitromethane or tolu- [ ene, [3,18] leading to decomposition of 3 and 4 and, therefore, moderate yields. Some improvement has been achieved by the use of 1,2-dichloroethane as solvent [19] or ferric chloride [20] or trimethylsilyl triflate [21] as the promoter.…”

Section: Introductionmentioning

confidence: 99%