Hayashi rearrangement
The Hayashi rearrangement is the chemical reaction of ortho-benzoylbenzoic acids catalyzed by sulfuric acid or phosphorus pentoxide.{{cite journal
| title = A new isomerism of halogenohydroxybenzoyltoluic acids
| author = Mosuke Hayashi
| journal = Journal of the Chemical Society
| volume =
| issue =
| pages = 2516
| year = 1927
| url =
| doi = 10.1039/JR9270002516 }} {{cite journal
| title = A new isomerism of halogenohydroxybenzoyltoluic acids. Part II. 2-(5-Chloro-2-hydroxybenzoyl)-5(4?)-methylbenzoic acid
| author = Mosuke Hayashi
| journal = Journal of the Chemical Society
| volume =
| issue =
| pages = 1513
| year = 1930
| url =
| doi = 10.1039/JR9300001513}}; p. 1520 {{doi|10.1039/JR9300001520}}; p. 1524{{doi|10.1039/JR9300001524}}
File:Hayashi_Rearrangement_Scheme.png
This reaction proceeds through electrophilic acylium ion attack with a spiro intermediate.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}}Name Reactions: A Collection of Detailed Reaction Mechanisms By Jie Jack Li Published 2003 Springer {{ISBN|3-540-40203-9}}
