Ir-Catalyzed, Stereoselective Total Synthesis of (+)-Rubriflordilactone A
Jun-Jie Liu1,2, Zhi-Bin Ni1,2, Lei Li1
1State Key Laboratory of Phytochemistry and Natural Medicines, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.
Abstract:
A stereocontrolled asymmetric total synthesis of the Schisandra nortriterpenoid (+)-rubriflordilactone A employing Krische's Ir-catalyzed 2-(alkoxycarbonyl)allylation for late-stage γ-butenolide formation is described. Additional noteworthy aspects include the integration of Carreira's Ir/amine dual-catalyzed allylation, Suzuki coupling, and Catellani reaction, resulting in the formation of an indane iodide. The alkylation of lactone 7, followed by RCM, A-ring formation via condensation of the B-ring lactone with Bestmann ylide, and Morken's Pt-catalyzed diboration/oxidation, facilitates the stereoselective formation of the ABCDEF ring system.
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