Base-Mediated Ring-Contraction of Pyran Systems Promoted by Palladium and Phase-Transfer Catalysis

Stuart Aiken, Orlando De Azevedo, Kieran Chauhan, Thomas Driscoll, Paul Elliott, Christopher Gabbutt, Mark Heron

Research output: Contribution to journalArticle


A study of the ring-contraction of a model 3H-naphtho[2,1-b]pyran is described to elucidate and optimize the ring-contraction of naphthopyrans. Two efficient base-mediated protocols to access multiple naphthofurans, naphthodifurans, and a benzo-fused indole in generally good yields are reported. Furthermore, a protocol to selectively prepare (hetero)aryl-substituted naphthofurans via a Suzuki-coupling–ring-contraction process is presented. An additional protocol that allows Suzuki cross-coupling reactions to be performed on bromo-substituted naphthopyrans without the ring-contraction side reaction is reported.
Original languageEnglish
Pages (from-to)952-966
Number of pages15
JournalJournal of Organic Chemistry
Issue number2
Early online date20 Dec 2019
Publication statusPublished - 20 Dec 2019


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