91965-40-1Relevant academic research and scientific papers
Concise Construction of the ACDE Ring System of Calyciphylline A Type Alkaloids by a [5+2] Cycloaddition
Nakamura, Hugh,Kawakami, Manami,Tsukano, Chihiro,Takemoto, Yoshiji
, p. 8701 - 8704 (2019)
A concise route for construction of the ACDE ring skeleton in calyciphylline A type alkaloids was developed using an intramolecular [5+2] cycloaddition reaction of an oxidopyrylium species bearing a tetrasubstituted olefin. Key to the success of this reaction was the combination of acid and base, which accelerated the construction of this skeleton containing a spiro ring and vicinal quaternary carbon centers. The resultant tricyclic ADE ring compound was converted to an ACDE ring model through C?H oxidation and an aza-Wittig reaction.
