Dihydropyridines in synthesis and biosynthesis. IV. Dehydrosecodine, in vitro precursor of indole alkaloids

Abstract
The synthesis of the two isomeric dehydrosecodines is described. Stabilization of these systems is achieved by chromium carbonyl complexation of the dihydropyridine unit in these molecules. Reaction of the complexes with pyridine, or preferably ethylenediamine, allows insitu generation of the dehydrosecodines. A study of their chemistry and conversion to alkaloid systems is presented.