Abstract
N-Acetylneuraminic acid (Neu5Ac) and its various analogs are critical components of cell surface glycoconjugates involved in cellular recognition processes. Human parainfluenza virus type 1 (hPIV-1) is a serious pathogen causing upper and lower respiratory disease in infants and young children. 3,4-Unsaturated sialic acid derivatives are a promising candidate as transition-state analogs for the enzyme reaction. We present our results on the interesting use of Bi(OTf)3- montmorillonite K-10 as an efficient catalyst for the synthesis of 3,4-unsaturated sialic acid derivative via the Ferrier glycosylation reaction starting from sialic acid 4,5-oxazoline derivative. Furthermore, we found that glycosylation reaction of imidate derivative prepared from sialic acid 4,5-oxazoline derivative with alcohols catalyzed by AgOTf or Pd catalyst gave a variety of 3,4-unsaturated sialic acids in moderate yields.
