Résumé
An isomer of
N-acetylneuraminic acid (Neu5Ac) with the acetamido group at C-4 (iso-Neu4Ac) has been synthesized through stereoselective 1,4-conjugate addition of trimethylsilyl azide to a 2-thiazolyl α,β-enone bearing a protected D-mannose moiety at C-β. The same approach employing benzylamine as aminating reagent was less viable. In both routes the thiazole ring serves as a precursor to the formyl group which is oxidized to carboxylic acid in the final step of the synthesis.
An isomer of
N-acetylneuraminic acid with the acetamido group at C-4 has been synthesized through stereoselectivel,4-conjugate addition of trimethylsilyl azide to a 2-thiazolyl α,β-enone bearing a protected D-mannose moiety at C-β.