Rapid Construction of Bisindole Alkaloids Caulersin and Racemosin B From Methyl 3-Indolylpyruvate Based on a Biomimetic Dimerization Strategy

Attempts to directly construct bisindole alkaloids caulerpin and caulersin resulted in the discovery of novel synthetic approaches to a specific bisindole framework with a central troponoid core and an unexpected product-racemosin B. The developed biomimetic domino sequences were triggered by a dimerization process from a shared precursor, methyl 3-indolylpyruvate. Thus, caulersin and racemosin B could be produced in 1 and 2 step processes.