A Concise Total Synthesis of the Stereoisomers of (-)-Pochonicine

A concise total synthesis of the four stereoisomers of (-)-pochonicine was undertaken. The key steps of the synthesis involved chemoselective debenzylation of the primary benzyloxy group and an unprecedented Na-Hg-mediated concomitant N-detosylative intramolecular epoxide ring-opening reaction. Notably, additional steps for the protection of other functional groups were not required. Glycosidase inhibition studies revealed that these compounds are inhibitors of beta-N-acetylglucosaminidase with IC50 values in the sub-millimolar range.