The Hayashi rearrangement is the chemical reaction of ortho-benzoylbenzoic acids catalyzed by sulfuric acid or phosphorus pentoxide.
This reaction proceeds through electrophilic acylium ion attack with a spiro intermediate.
References
Mosuke Hayashi (1927). "A new isomerism of halogenohydroxybenzoyltoluic acids". Journal of the Chemical Society: 2516. doi:10.1039/JR9270002516. /wiki/Journal_of_the_Chemical_Society ↩
Mosuke Hayashi (1930). "A new isomerism of halogenohydroxybenzoyltoluic acids. Part II. 2-(5-Chloro-2-hydroxybenzoyl)-5(4?)-methylbenzoic acid". Journal of the Chemical Society: 1513. doi:10.1039/JR9300001513.; p. 1520 doi:10.1039/JR9300001520; p. 1524doi:10.1039/JR9300001524 /wiki/Journal_of_the_Chemical_Society ↩
The Hayashi Rearrangement of Substituted o-Benzoylbenzoic Acids Reuben B. Sandin, Russell Melby, Robert Crawford, and Donald McGreer J. Am. Chem. Soc. 1956 pp 3817 - 3819; doi:10.1021/ja01596a069 /wiki/J._Am._Chem._Soc. ↩
Name Reactions: A Collection of Detailed Reaction Mechanisms By Jie Jack Li Published 2003 Springer ISBN 3-540-40203-9 /wiki/ISBN_(identifier) ↩