Electrophilic substitution reaction of indole, part XXIV: Synthesis, characterization, and crystal structure of a novel heterocyclic compound

The reaction of indole with cyclohexanone in the presence of the Lewis acid, boron trifluoride diethyl etherate, resulted in the synthesis of a novel and interesting product () in addition to the bis(indolyl)methane system (). The structure of this novel compound has been determined by NMR (1H and 13C) and X-ray crystal structure analysis. Compound is a (1:2) addition reaction product of indole with cyclohexanone. The spiro six-membered ring is in the classic chair conformation. An epoxide bridge at C-4a/C-10b and the two hydroxyl groups at C-5a, C-10a are all on the same side of the central five membered ring. J. Heterocyclic Chem., (2011).