Direct synthesis of 2-arylazulenes by [8+2] cycloaddition of 2H-cyclohepta[b]furan-2-ones with silyl enol ethers
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Updated: Dec 31, 2025

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Taku Shoji1, Shuhei Sugiyama, Yoshiaki Kobayashi
1Department of Material Science, Graduate School of Science and Technology, Shinshu University, Matsumoto 390-8621, Nagano, Japan. tshoji@shinshu-u.ac.jp.
Abstract:
We developed a procedure for the direct synthesis of 2-arylazulenes, which were obtained in moderate to excellent yields, by [8+2] cycloaddition of 2H-cyclohepta[b]furan-2-ones with aryl-substituted silyl enol ethers. The structures of some 2-arylazulenes were clarified by single-crystal X-ray analysis. The 2-phenylazulene derivatives obtained by this study showed noticeable fluorescence in acidic media.
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