Synthesis
DOI: 10.1055/a-2788-9051
Paper

Controlled Conversion of C3-Ketoxime Triterpenoids to A-Lactam or A-seco-Nitrile Scaffolds

Authors

  • Catherine Bergeron

    1   Faculty of Pharmacy, Université Laval, Quebec, Canada (Ringgold ID: RIN4440)
  • Christopher Bérubé

    1   Faculty of Pharmacy, Université Laval, Quebec, Canada (Ringgold ID: RIN4440)
  • Maxime Del Mistro

    1   Faculty of Pharmacy, Université Laval, Quebec, Canada (Ringgold ID: RIN4440)
  • Simon Côté

    2   Research and Development, Matrix Innovation, Quebec, Canada
  • Dave Richard

    3   Department of microbiology, infectiology and immunology, Université Laval, Quebec, Canada (Ringgold ID: RIN4440)
  • Eric Biron

    1   Faculty of Pharmacy, Université Laval, Quebec, Canada (Ringgold ID: RIN4440)

Supported by: Natural Sciences and Engineering Research Council of Canada ALLRP 567473-21,ALLRP 586210-23

In this work, we report the investigation of several Beckmann rearrangement conditions to selectively produce seven-membered A-lactam and A-seco-nitrile derivatives from triterpenoids. Using C3-oxime-C28-acetate betulin as a model substrate, the presence of zinc chloride in the reaction gave the best yields of either the amide or the ring-opened nitrile products but the preference between the Beckmann rearrangement versus fragmentation was dictated by the solvent used. The scope of the reaction was extended to other triterpenoids such as lupeol, betulinic acid, and oleanolic acid. Convenient and safe, the reported method was performed on scales up to 20 g, employs cost-effective reagents, and allows the rapid generation of attractive triterpenoid scaffolds and potentially bioactive molecules.



Publication History

Received: 14 November 2025

Accepted after revision: 14 January 2026

Accepted Manuscript online:
14 January 2026

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