Chiral Indolizinium Salts Derived from 2-Pyridinecarbaldehyde—First Diastereoselective Syntheses of (−)-1-<i>epi-</i>lentiginosine

Abstract

The first diastereoselective synthesis of (−)-1-epi-lentiginosine from a common chiral trans-epoxyamide derived from 2-pyridincarbaldehyde is reported. This methodology involves a sequential oxirane ring opening and intramolecular 5-exo-tet cyclization of tosylate trans-epoxyalcohol to afford a diastereomeric mixture of indolizinium salts in a one-pot fashion, followed by regio- and diastereospecific pyridinium ring reduction.

Keywords

• diastereoselective synthesis
• (−)-1-<i>epi</i>-lentiginosine
• <i>trans</i>-epoxyamides
• indolizinium salts