Synthetic Studies on Sialoglycoconjugates 17: Synthesis of 4-O-, 9-O-, and 4,9-Di-O-Acetyl-N-Acetylneuraminic Acids and their Derivatives

Abstract

4-O-, 9-O-, and 4,9-Di-O-acetyl derivatives 9, 13, and 23 of N-acetylneuraminic acid were synthesized from methyl (methyl 5-acetamido-3,5-di-deoxy-2-thio-D-glycero-α-D-galacto-2-nonulopyranosid)onate (1) or methyl [2-(trimethylsilyl)ethyl 5-acetamido-3,5-dideoxy-D-glycero-α-D-galacto-2-nonulopyranosid)onate (14). In addition, the suitably protected derivatives 7 and 11 of the 4-O- and 9-O-acetyl derivatives, which could be used as the glycosyl donors for the synthesis of gangliosides containing the O-acetyl group at C-4 or C-9 in N-acetylneuraminic acid moiety, were synthesized.