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, Québec, Canada (Ringgold ID: RIN4440)
    2   Centre de recherche du CHU de Québec-Université Laval, Québec, Canada
    3   Centre de recherche en infectiologie, Université Laval, Québec, Canada
  • Christopher Bérubé

    1   Faculty of Pharmacy, Université Laval, Québec, Canada (Ringgold ID: RIN4440)
    2   Centre de recherche du CHU de Québec-Université Laval, Québec, Canada
    3   Centre de recherche en infectiologie, Université Laval, Québec, Canada
  • Maxime Del Mistro

    1   Faculty of Pharmacy, Université Laval, Québec, Canada (Ringgold ID: RIN4440)
    2   Centre de recherche du CHU de Québec-Université Laval, Québec, Canada
    3   Centre de recherche en infectiologie, Université Laval, Québec, Canada
  • Simon Côté

    4   Research and Development, Matrix Innovation Inc., Québec, Canada
  • Dave Richard

    2   Centre de recherche du CHU de Québec-Université Laval, Québec, Canada
    3   Centre de recherche en infectiologie, Université Laval, Québec, Canada
    5   Département de microbiologie, infectiologie et immunologie, Faculté de médecine, Université Laval, Québec, Canada (Ringgold ID: RIN4440)
  • Eric Biron

    1   Faculty of Pharmacy, Université Laval, Québec, Canada (Ringgold ID: RIN4440)
    2   Centre de recherche du CHU de Québec-Université Laval, Québec, Canada
    3   Centre de recherche en infectiologie, Université Laval, Québec, Canada

Natural Sciences and Engineering Research Council of Canada (NSERC) # ALLRP 567473-21


Graphical Abstract

Abstract

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

Article published online:
26 January 2026

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