Synthesis of Novel Indolo-Spirocyclic Compounds: Synthesis of Novel Indolo-Spirocyclic Compounds

In the present work, we succeeded to synthesize the novel indolo-spirocyclic compounds (4, 5, 6, 7 and 11) via electrophilic condensation reactions of indoles with carbonyl compounds including different types of ketones, for example, heteroacetyl ketones (3-acetylindole and 3-acetylpyridine), cyclohexanone, isatin, cyclohexane-1,4-dione, whereas an attempt to prepare the spirocyclic 9 failed. This new idea will open a high prospective for continuous investigations related to the synthesis of novel indolo-spirocyclic compounds.