Unprecedented Stereospecific Synthesis of a Novel Tetracyclic Ring System, a Hybrid of Tetrahydropyrrolo[2,3-<i>b</i>]indole and Tetrahydroimidazo[1,2-<i>a</i>]indole, via a Domino Reaction upon a Tryptophan-Derived Amino Nitrile

Abstract

Compounds containing a novel tetracyclic ring system, a hybrid of tetrahydropyrrolo[2,3-b]indole and tetrahydroimidazo[1,2-a]indole, are synthesized via an acid-mediated stereospecific domino tautomerization of a tryptophan-derived alpha-amino nitrile. Characterization of these new compounds and preliminary studies on the reactivity of the tetracyclic heterocyclic system are reported. [reaction: see text]