Unexpected synthesis of a novel heterocyclic system – (7E,10aE)-2,7-Dimethylfuro[3′,4′:6,7]cycloocta[1,2,3-cd]indole-8,10(2H,6H)-dione

• Published in: Tetrahedron letters 2017-07, Vol.58 (27), p.2648-2650
• Main Authors: Rybalkin, Vladimir P., Borodkin, Gennadii S., Tkachev, Valerii V., Yu. Zmeeva, Sofiya, Popova, Lidiya L., Dubonosov, Alexander D., Bren, Vladimir A., Aldoshin, Sergey M., Minkin, Vladimir I.
• Format: Article
• Language: English
• Subjects: (7E,10aE)-2,7-Dimethylfuro[3′,4′:6,7]cycloocta[1,2,3-cd]indole-8,10(2H,6H)-dione; Fulgides; Stobbe condensation
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2017.05.062

[Display omitted] •Novel furocycloocta[c,d]indole heterocyclic system was synthesized.•The Stobbe condensation was used on the first two stages.•The structure was confirmed by 1H, 13C NMR and single crystal X-ray diffraction. The first derivative of a novel heterocyclic system, (7E,10aE)-2,7-dimethylfuro[3′,4′:6,7]-cycloocta[1,2,3-cd]indole-8,10(2H,6H)-dione, was synthesized based on the Stobbe condensation of 3-chloro-1-methylindole-2-carbaldehyde with diethyl isopropylidenesuccinate. Cyclization of the 2-indolyl-containing diacid, formed by subsequent hydrolysis of the condensation product, did not lead to the expected fulgide, but rather to an unprecedented tetracyclic compound, the structure of which was established by 1H, 13C NMR, IR spectroscopy, mass-spectrometry and single crystal X-ray diffraction.