Arnaud PastorRohen PrinslooKristen N. BurfordAndrew R. MacdonaldMasood ParvezChris GendyThomas G. Back2023-09-212023-09-212023-09-180022-3263https://hdl.handle.net/1880/11718310.11575/PRISM/42025Supplementary materials associated with this article are available: Back, Thomas, 2023, "Synthesis of the Marine Alkaloid Cylindricine C and Serendipitous Synthesis of its 2,13-Di-epi Stereoisomer", https://doi.org/10.5683/SP3/YLTS4G, Borealis, V1 This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Organic Chemistry, copyright © 2023 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi-org/10.1021/acs.joc.3c01467A new approach to the marine alkaloid cylindricine C afforded its previously unreported (±)-2,13-di-epi stereoisomer as the major product along with a minor amount of the racemic parent alkaloid. Key steps included a stereoselective dianion alkylation of a monoester of 1,2-cyclohexanedicarboxylic acid and an annulation based on the tandem conjugate addition of a primary amine to an acetylenic sulfone, followed by intramolecular acylation of the resulting sulfone-stabilized carbanion. The cis-azadecalin moiety thus formed, comprising the cyclohexane A-ring and enaminone B-ring of the products, was further elaborated by the selenenyl chloride-induced cyclofunctionalization of a pendant butenyl substituent with the enaminone moiety, followed by a seleno-Pummerer reaction. Desulfonylation and enaminone reduction afforded the final products. Molecular modeling and X-ray crystallography provided further insight into these processes.enUnless otherwise indicated, this material is protected by copyright and has been made available with authorization from the copyright owner. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.Attribution-NonCommercial 4.0 Internationalhttp://creativecommons.org/licenses/by-nc/4.0/Article10.1021/acs.joc.3c01467