First total synthesis of concavine† †Electronic supplementary information (ESI) available. CCDC 1523963. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6sc05627j Click here for additional data file. Click here for additional data file.

The synthesis of the unusual alkaloid concavine, isolated from Clitocybe concava (Basidiomycetae), has been accomplished. The synthetic route features regioand stereoselective manipulation of polycyclic imide intermediates via enolate substitution and Grignard addition, along with a key bridge-forming step involving a new method for sulfenylative radical cyclisation. The NMR data for synthetic concavine demonstrate that the original data reported for the natural product refer to the derived acetic acid salt, probably formed as an artefact of isolation or purification.