SYNTHESES OF (α2-9) and (α2-8) LINKED DINEURAMINYL SACCHARIDES BY USE OF 2Β-BROMO-3Β-HYDROXY-4,7,8,9-TETRA-O-ACETYL-N-ACETYLNEURAMINIC ACID METHYL ESTER

Article abstract of DOI:10.1016/S0040-4020(01)85909-3

NeuAc(α2-9)NeuAc and NeuAc(α2-8)NeuAc disaccharides, which are involved in the group C meningococcal polysaccharides and gangliosides, were synthesized by condensation of the acetyl protected 2-deoxy-2,3-dehydroneuraminic acid methyl ester having a hydroxyl group at 9 or 8 position with the acetyl protected 2β-bromo-3β-hydroxy-N-acetylneuraminic ester in preference to the corresponding β-glycosides.The hydroxyl groups of the obtained glycosides were removed by phenoxythiocarbonylation followed by reduction with tributylstannane and the resultant disaccharides were deprotected to afford the free glycosides in good yields.