Syntheses of 2-deoxy-2,3-didehydro-N-acetylneuraminic acid analogues modified by α-acylaminoamido groups at the C-4 position using isocyanide-based four-component coupling and biological evaluation as inhibitors of human parainfluenza virus type 1.

Novel sialidase inhibitors 11 having an α-acylaminoamido group at the C-4 position of Neu5Ac2en 1 against human parainfluenza virus type 1 (hPIV-1) were synthesized using one-pot isocyanide-based four-component condensation, and their inhibitory activities against hPIV-1 sialidase were studied. Compound 11b showed inhibitory activity (IC(50)=5.1 mM) against hPIV-1 sialidase. The degree of inhibition of 11b was much weaker than that of 1 (IC(50)=0.3 mM).