Lam PH, Kerkovius JK, Reisman SE. A Pyridine Dearomatization Approach for the Gram Scale Synthesis of (±)-Sparteine.
Org Lett 2023;
25:8230-8233. [PMID:
37948657 PMCID:
PMC10683365 DOI:
10.1021/acs.orglett.3c03242]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/05/2023] [Accepted: 11/07/2023] [Indexed: 11/12/2023]
Abstract
Both enantiomers of sparteine have suffered from pricing and supply chain variability, which has inspired efforts toward efficient chemical synthesis. Here, we build upon our reported synthesis of the matrine-type lupin alkaloids in order to synthesize (±)-sparteine. Specifically, selective quenching of the cyclization between glutaryl chloride and pyridine with methanol provides a functionalized quinolizidine core that was elaborated to (±)-sparteine in six additional steps on gram scale. This synthesis provides a scalable route to sparteine from inexpensive commodity chemicals utilizing a dearomative cyclization. In addition, this route provides concise access to (±)-lupinine.
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