As a precursor for the chemical synthesis of sialylated oligosaccharid
es, the trisaccharide glycoside Neu5Ac alpha(2-8)Galbeta(1-4)GlcNAcbet
a(1-O)-pent-4-ene was synthesized starting from GlcNAcbeta(1-O)-pent-4
-ene, UDP-glucose and N-acetylneuraminic acid in a one pot reaction em
ploying galactosyltransferase and alpha(2-6)sialyl-transferase in a co
mplete cofactor regeneration system.