Synthesis and study of the glycosyl-donor properties of 2-(2,2,2-trichloroethoxy)-(3,4,6-tri-O-acetyl-1,2-dideoxy-α-d-galactopyrano)-[2,1-d]-2-oxazoline

• Published in: Carbohydrate research Vol. 536; p. 109040
• Main Authors: Pertel, Sergey S., Kakayan, Elena S., Zinin, Alexander I., Kononov, Leonid O.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.02.2024
• Subjects: 1,2-trans-stereoselective glycosyl donors; 2-alkoxy glyco-[2,1-d]-2-oxazolines; Chemoselective glycosylation; d-Galactosamine; Oligosaccharide synthesis; Polymerization of 2-alkoxy-2-oxazoline derivatives; Oligosaccharide synthesis; Polymerization of 2-alkoxy-2-oxazoline derivatives; 1,2-trans-stereoselective glycosyl donors; Chemoselective glycosylation; d-Galactosamine; 2-alkoxy glyco-[2,1-d]-2-oxazolines
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/j.carres.2024.109040

A synthesis of 2-(2,2,2-trichloroethoxy)-(3,4,6-tri-O-acetyl-1,2-dideoxy-α-d-galactopyrano)-[2,1-d]-2-oxazoline – a previously unknown 2-alkoxy glyco-[2,1-d]-2-oxazoline derivative with d-galacto configuration was carried out. Glycosylating activity of the obtained galactooxazoline has been studied and it has been shown that in the presence of a weak protic acid, such as sym-collidinium triflate, this substance exhibits properties of a reactive and 1,2-trans-stereoselective glycosyl donor. The homopolymerization reaction of oxazoline derivatives of sugars has been found to proceed under the same conditions, leading to the formation of pseudo-oligosaccharide products. It has been found that this undesirable side reaction could be suppressed by changing the acid catalyst concentration, resulting in the development of efficient methods for the synthesis of glycoside and oligosaccharide derivatives of β-d-galactosamine using the synthesized 2-(2,2,2-trichloroethoxy)-2-oxazoline glycosyl donor under very mild conditions. [Display omitted] •The synthesis of a 2-(2,2,2-trichloroethoxy) glyco-[2,1-d]-2-oxazoline derivative with the d-galacto configuration was carried out.•The obtained galactooxazoline 4 exhibits properties of a reactive and 1,2-trans-stereoselective glycosyl donor and can be used for the synthesis of N-Troc-protected oligosaccharide derivatives of d-galactosamine.•The homopolymerization reaction of oxazoline 4 was found to proceed under the conditions of the glycoside synthesis, leading to the formation of pseudo-oligosaccharide products.•The undesired homopolymerization of oxazoline 4 was found to be suppressed by varying the concentration of the acid catalyst.