Synthesis of sialyl halides with various acyl protective groups

• Published in: Carbohydrate research Vol. 536; p. 109033
• Main Authors: Mamirgova, Zarina Z., Zinin, Alexander I., Chizhov, Alexander O., Kononov, Leonid O.
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01.02.2024; Elsevier
• Subjects: Biochemistry & Molecular Biology; Chemistry; Chemistry, Applied; Chemistry, Organic; Life Sciences & Biomedicine; Physical Sciences; Science & Technology; Sialic acid; Sialyl bromides; Sialyl donors; Sialyl halides; Transacylation; Sialic acid; Sialyl bromides; Sialyl halides; Transacylation; Sialyl donors; MECHANISM; STEREOSELECTIVE SIALYLATION; DONORS; ACETYL-NEURAMINIC ACID; ALPHA-SIALYLATION; CATION CLOCK REACTIONS; CHEMICAL GLYCOSYLATION; GLYCOSIDATION; DERIVATIVES; N-ACETYLNEURAMINIC ACID
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/j.carres.2024.109033

Glycosyl halides are historically one of the first glycosyl donors used in glycosylation reactions, and interest in glycosylation reactions involving this class of glycosyl donors is currently increasing. New methods for their activation have been proposed and effective syntheses of oligosaccharides with their participation have been developed. At the same time, the possibilities of using these approaches to the synthesis of sialosides are restricted by the limited diversity of known sialyl halides (previously, mainly sialyl chlorides, less often sialyl bromides and sialyl fluorides, with acetyl (Ac) groups at the oxygen atoms and AcNH, Ac2N and N3 groups at C-5 were used). This work describes the synthesis of six new N-acetyl- and N-trifluoroacetyl-sialyl chlorides and bromides with O-chloroacetyl and O-trifluoroacetyl protective groups. Preparation of N,O-trifluoroacetyl protected derivatives was made possible due to development of the synthesis of sialic acid methyl ester pentaol with N-trifluoroacetyl group. [Display omitted] •New sialyl donors with different N- and O-acyl protective groups were prepared.•Six new N-acetyl and N-trifluoroacetyl sialyl chlorides and bromides were prepared.•Pure sialic acid methyl ester pentaol with N-trifluoroacetyl group was prepared.•Anomeric configuration was established by measuring 3JC-1,H-3ax coupling constants.•Direct exchange of N-acetyl group with N-trifluoroacetyl group was studied.