Synthesis 2019; 51(09): 2001-2006
DOI: 10.1055/s-0037-1612063
paper
© Georg Thieme Verlag Stuttgart · New York

Tungsten-Promoted Hetero-Pauson–Khand Cycloaddition: Application to the Total Synthesis of (–)-Allosecurinine

Egor Chirkin
,
Chouaha Bouzidi
,
Laboratoire de Pharmacognosie UMR CNRS 8638, Faculté de Pharmacie, Université Paris Descartes, 4 Avenue de l’Observatoire, 75006 Paris, France   Email: francois-hugues.poree@parisdescartes.fr
› Author Affiliations
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Publication History

Received: 06 December 2018

Accepted after revision: 17 December 2018

Publication Date:
18 February 2019 (online)


Abstract

Herein, we report a concise enantioselective synthesis of (–)-allosecurinine, a tetracyclic Securinega alkaloid featuring an α,β-unsaturated γ-lactone moiety. Starting from inexpensive and readily available trans-l-hydroxyproline, our strategy entails a rare late-stage [2+2+1]-hetero-Pauson–Khand cycloaddition between a ketone and an alkyne as the key complexity-generating step to rapidly install the CD-ring system. The reported W(CO)6-promoted intramolecular cyclization provides the first example of a tungsten-mediated hetero-Pauson–Khand reaction. This approach to the strained bicyclic CD motif present in ­allosecurinine provides some insights into the boundaries of this potentially powerful methodology that might be further extended to other butenolide-containing natural products.

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