Riedel S, Maichle-Mössmer C, Maier ME. Intramolecular Diels-Alder Reactions of Tethered Enoate Substituted Furans Induced by Dialkylaluminum Chloride.
J Org Chem 2017;
82:12798-12805. [PMID:
29111737 DOI:
10.1021/acs.joc.7b02117]
[Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Gold(I)-catalyzed cycloisomerization of enynols 11 and 17, obtained by Sonogashira coupling, led to the tethered enoate-substituted furans 14 and 19. While attempts at thermal and several Lewis acid induced intramolecular Diels-Alder reactions remained fruitless, dialkylaluminum chloride led to the formation of hexahydroindene and octahydronaphthalene derivatives 20-23. Their formation can be explained by Lewis acid induced opening of the epoxy bridge with transfer of one alkyl group to the intermediate cycloadduct.
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