1229311-68-5Relevant academic research and scientific papers
Why Is Direct Glycosylation with N-Acetylglucosamine Donors Such a Poor Reaction and What Can Be Done about It?
Marqvorsen, Mikkel H. S.,Pedersen, Martin J.,Rasmussen, Michelle R.,Kristensen, Steffan K.,Dahl-Lassen, Rasmus,Jensen, Henrik H.
, p. 143 - 156 (2017/04/26)
The monosaccharide N-acetyl-d-glucosamine (GlcNAc) is an abundant building block in naturally occurring oligosaccharides, but its incorporation by chemical glycosylation is challenging since direct reactions are low yielding. This issue, generally agreed upon to be caused by an intermediate 1,2-oxazoline, is often bypassed by introducing extra synthetic steps to avoid the presence of the NHAc functional group during glycosylation. The present paper describes new fundamental mechanistic insights into the inherent challenges of performing direct glycosylation with GlcNAc. These results show that controlling the balance of oxazoline formation and glycosylation is key to achieving acceptable chemical yields. By applying this line of reasoning to direct glycosylation with a traditional thioglycoside donor of GlcNAc, which otherwise affords poor glycosylation yields, one may obtain useful glycosylation results.
Direct chemical glycosylation with pentenyl- and thioglycoside donors of N-acetylglucosamine
Krag, Jonas,Christiansen, Mira S.,Petersen, Jette G.,Jensen, Henrik H.
experimental part, p. 872 - 879 (2010/06/19)
The use of pentenyl and thiophenyl glycosides of N-acetylglucosamine (GlcNAc) as glycosyl donors for the direct preparation of O-glycosides of GlcNAc promoted by N-iodosuccinimide (NIS) and metal triflates in dichloromethane has been investigated. Both glycosyl acceptors 1-octanol and (-)-menthol resulted in good glycosylation yields for both types of donors with pentenyl glycosides being somewhat superior in terms of yield. Carbohydrate-based acceptors were reacted with a benzylated GlcNAc-pentenyl donor but only provided disaccharides in poor to moderate yields. The results show that a variety of metal triflates are capable of acting as an activator for both NIS and the intermediate oxazoline.
