A short synthesis of N(a)-methylervitsine. Reactivity of the intermediate 1,4-dihydropyridine towards electrophiles
Abstract
A four-step synthesis of N(a)-methylervitsine involving the nucleophilic addition of the enolate derived from acetylindole 2 to pyridinium salt 3, with subsequent C6H5SeBr-promoted cyclization of the resulting 1,4-dihydropyridine and further elaboration of the exocyclic 20E-ethylidene and 16-methylene substituents, is reported.