SYNTHETIC STUDIES ON SIALOGLYCOCONJUGATES .17. SYNTHESIS OF 4-O-ACETYL-N-ACETYLNEURAMINIC, 9-O-ACETYL-N-ACETYLNEURAMINIC, AND 4,9-DI-O-ACETYL-N-ACETYLNEURAMINIC ACIDS AND THEIR DERIVATIVES

4-0-, 9-0-, and 4,9-Di-O-acetyl derivatives 9, 13, and 23 of N-acetylneuraminic acid were synthesized from methyl (methyl 5-acetamido-3,5-dideoxy-2-thio-D-glycero-α-D-Kalacto-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 4-0- and 9-O-acetyl derivatives, which could be used as the glycosyl donors for the synthesis of gangliosides containing the 0-acetyl group at C-4 or C-9 in N-acetylneuraminic acid moiety, were synthesized. © 1990, Taylor & Francis Group, LLC. All rights reserved.