A biomimetic synthesis of (−)-N(a)-methylervitsine
Abstract
A straightforward, biomimetic synthesis of
(−)-N(a)-methylervitsine involving the
nucleophilic addition of the enolate derived from 2-acetylindole 1 to
chiral, non-racemic pyridinium salt 2, followed by
(Me2N+CH2) I–
induced cyclization of the resultant 1,4-dihydropyridine, with subsequent
elaboration of the exocyclic 16-methylene and 20E-ethylidene
substituents, is reported.