화학공학소재연구정보센터
Journal of the American Chemical Society, Vol.136, No.42, 15102-15108, 2014
Unified Strategy to Monoterpene lndole Alkaloids: Total Syntheses of (+/-)-Goniomitine, (+/-)-1,2-Dehydroaspidospermidine, (+/-)-Aspidospermidine, (+/-)-Vincadifformine, and (+/-)-Kopsihainanine A
Total syntheses of (+/-)-goniomitine, (+/-)-1,2-dehydroaspidospermidine, (+/-)-aspidospermidine, (+/-)-vincadifformine, and (+/-)-kopsihainanine A were achieved featuring two common key steps: (1) a palladium-catalyzed decarboxylative vinylation that provides quick access to cyclopentene intermediates containing all of the carbons present in the natural products and (2) an integrated oxidation/reduction/cyclization (iORC) sequence for skeletal reorganization that converts the cyclopentenes to the pentacyclic structures of the natural products. By incorporation of a geometric constraint to iORC substrates, both the chemoselectivity (C7 vs N1 cyclization) and the stereoselectivity (trans- vs cis-fused ring system) of the cyclization process can be controlled.