Synthesis and glycosidase inhibition of the enantiomer of (-)-steviamine, the first example of a new class of indolizidine alkaloid

(+)-Steviamine, the enantiomer of the natural (-)-steviamine, and its corresponding C5 epimer have been synthesized from the d-ribose-derived cyclic nitrone. (-)-Steviamine was found to be the first naturally occurring iminosugar that causes any inhibition of α-galactosaminidases. © 2010 American Chemical Society.