Amino Acid-Based Synthesis and Glycosidase Inhibition of Cyclopropane-Containing Iminosugars.

Synthesis of four iminosugars fused to a cyclopropane ring is described using l-serine as the chiral pool. The key steps are large-scale preparation of an α,β-unsaturated piperidinone followed by completely stereoselective sulfur ylide cyclopropanation. Stereochemistry of compounds has been studied by nuclear Overhauser effect spectroscopy (NOESY) experiments and H homonuclear decoupling to measure constant couplings. The activity of these compounds against different glycosidases has been evaluated. Although inhibition activity was low (compound presents a ( ) of 1.18 mM against β-galactosidase from ), interestingly, we found that compounds and increase the activity of neuraminidase from up to 100%.