Preparation and H(3) Isomerization of C(15)-Substituted Deplancheine Derivatives. Synthesis of Geissoschizol and Geissoschizine

Article abstract of DOI:10.1021/jo00266a032

A series of indolo<2,3-a>quinolizidines have been prepared by the two-step scheme of nucleophile addition to 1-tryptophyl-3-acylpyridinium salts or their vinylogues and subsequent, acid-catalyzed cyclization.Acid-induced hydrolysis, decarboxylation, and reduction of the resultant vinylogous urethanes has opened an approach to antirhine and yielded C(15)-substituted deplancheine derivatives.Functional group manipulation of the latter has permitted the syntheses of geissoschizol and geissoschizine.