Indirect Trapping of the Retroconjugate Addition Reaction Intermediate Involved in the Epimerization of Lobeline: Application to the Synthesis of (−)-Sedamine

Alkyl chloroformates induced indirect trapping of the retroconjugate addition reaction intermediate involved in the epimerization of lobeline is described. This strategy was applied to the conversion of (−)-lobeline to (−)-sedamine in high overall yield.