Syntheses of 9-Vinylated Benzotropolones by a Sequence of Acylation, Ring-Closing Enyne Metathesis, and Oxidation

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Sarah N. Momm - , University of Freiburg (Author)
  • Christian Seifried - , Chair of Organic Chemistry I, TUD Dresden University of Technology (Author)
  • Reinhard Brückner - , University of Freiburg (Author)

Abstract

Previous studies from our group revealed that 6,7-benzannulated nona-1,8-diene-5-ones of a variety of substitution patterns undergo ring-closing diene metatheses in the presence of the Grubbs-II catalyst; the benzocycloheptadienones formed thereby gave benzotropolones in between one and four follow-up steps. The present study discloses that exemplary 6,7-benzannulated non-1-en-8-yn-5-ones undergo ring-closing enyne metatheses in the presence of the Grubbs-II catalyst; the vinylated benzocycloheptadienones formed thereby gave 9-vinylbenzotropolones in four steps: silyl enol ether formation, Rubottom-type oxidation, desilylation, and Dess-Martin oxidation. The metathesis substrates were synthesized either from (ortho-bromoaryl)ethynes with an unsubstituted sp-carbon by a Br→Li exchange and an acylation with an H2C=CH-containing Weinreb amide; or, they were synthesized from (ortho-bromoaryl)ethynes with a trimethylsilylated sp-carbon by a Br→Li→ZnHal exchange, an acylation with an H2C=CH-containing thioester, and a desilylation.

Details

Original languageEnglish
Article numbere202301748
JournalChemistrySelect
Volume8
Issue number33
Publication statusPublished - 5 Sept 2023
Peer-reviewedYes

Keywords

ASJC Scopus subject areas

Keywords

  • Dess-Martin oxidation, enyne metathesis, Fukuyama acylation, non-benzenoid aromatics, ring-closing metathesis, Rubottom oxidation