unprotected pyridinium-polyol unit using Mitsunobu methodology. Subsequent PtO2-catalyzed diastereoselective hydrogenation of the pyridinium ring proceeded smoothly and led to the expected dihydroxyindolizidines with excellent yields. This stereochemically flexible strategy has been illustrated by the concise total synthesis of non-natural products derivatives such as (−)-lentiginosine and its stereoisomers