Total Synthesis of L-(+)-Swainsonine and Other Indolizidine Azasugars from D-Glucose

A total synthesis of L‐(+)‐swainsonine, a potent and specific inhibitor of naringinase, along with the syntheses of six unnatural indolizidine azasugars are reported by starting from D‐glucose. L‐(+)‐Swainsonine was synthesized in 14 steps in 17 % overall yield. Further, two of the indolizidine analogues were found to be good glycosidase inhibitors at micromolar concentrations. In all of these syntheses, the key step was an intramolecular SN2 reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) The total synthesis of L‐(+)‐swainsonine, a potent and specific inhibitor of naringinase, was achieved in 14 steps in 17 % overall yield by starting from D‐(+)‐glucose. The syntheses of six unnatural indolizidine azasugars are also reported, two of which were found to be good glycosidase inhibitors at micromolar concentrations.