Dihydropyridines in synthesis and biosynthesis. I. Secodine and precursors of dehydrosecodine

Abstract

A synthesis of 16,17-dihydrosecodin-17-ol and of secodine is described. Various indole derivatives were elaborated to a series of pyridinium salts, potential precursors for 1,2- and 1,6-dihydropyridine compounds exemplifying the proposed biointermediate dehydrosecodine [Catharanthus roseus alkaloid synthesis].