Synthesis of N-Acetyl-3-fluoro-neuraminic Acids

抄録

The addition of F₂ to methyl 5-acetamideo-2, 6-anhydro-4, 7, 8, 9-tetra-O-acetyl-2, 3, 5-trideoxy-D-glycero-D-galacto-non-2-enopyranosonate (6) in acetic acid gave a mixture of methyl 5-acetamido-4, 7, 8, 9-tetra-O-acetyl-2, 3, 5-trideoxy-2, 3-difluoro-β-D-erythro-L-gluco-2-nonulopyronosenate (7), methyl 5-acetamido-2, 4, 7, 8, 9-penta-O-acetyl-3, 5-dideoxy-3-fluoro-β-D-erythro-L-gluco-2-nonulosopyranosonate (8) and methyl 5-acetamido-2, 4, 7, 8, 9-penta-O-acetyl-3, 5-dideoxy-3-fluoro-β-D-erythro-L-manno-2-nonulopyranosonate (9). On the other hand, the addition of acetylhypofluorite to 6 in acetic acid gave 8 concomitant with small amounts of 7 and 9. The structural elucidation of 7, 8 and 9 on the basis of their ¹H-, ¹³C- and ¹⁹F-NMR spectra are described. Saponification of the ester groups of 7, 8 and 9 gave the corresponding N-acetyl 3-fluoro-neuraminic acids (14, 15 and 16). Compound 14 was a potent inhibitor against neuraminidase.