1354572-36-3Relevant academic research and scientific papers
Thionium ion initiated medium-sized ring formation: The total synthesis of asteriscunolide D
Trost, Barry M.,Burns, Aaron C.,Bartlett, Mark J.,Tautz, Thomas,Weiss, Andrew H.
, p. 1474 - 1477 (2012)
The first synthesis of the biologically active humulene natural product asteriscunolide D has been accomplished in nine steps without the use of protecting groups. The challenging 11-membered ring was forged via a diastereoselective thionium ion initiated cyclization, which constitutes a formal aldol disconnection to form a strained macrocycle. A stereospecific thioether activation-elimination protocol was developed for selective E-olefin formation, thus providing access to the most biologically active asteriscunolide. The absolute stereochemical configuration was established by the Zn-ProPhenol catalyzed enantioselective addition of methyl propiolate to an aliphatic aldehyde to afford a γ-hydroxy propiolate as a handle for butenolide formation via Ru-catalyzed alkene-alkyne coupling.
