title: Meldrum's acid-derived thione dienophile in a convergent and stereoselective synthesis of a tetracyclic quassinoid intermediate.
abstract: An advanced intermediate toward anti-cancer quassinoids has been synthesized using a quadruple diene-transmissive [4+2]-cycloaddition strategy. High convergence is achieved thanks to a regio- and stereoselective hetero-Diels-Alder reaction using a thione. The relative stereochemistry of the final Diels-Alder adduct was controlled by tethered substituents introduced via a highly syn- and gamma-selective vinylogous Mukaiyama aldol.
authors.affiliation: Département de Chimie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Perreault
authors.forename: Claude
authors.initials: C
authors.lastname: Spino
mesh_terms: D003500:Cyclization; D004146:Dioxanes / Q000737:chemistry*; D036702:Quassins / Q000138:chemical synthesis*; D013237:Stereoisomerism
chemical_list: D004146:Dioxanes; D036702:Quassins; C076489:Meldrum's acid