Kostanecki acylation
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The Kostanecki acylation is a method used in organic synthesis to form chromones{{Cite journal | doi = 10.1021/cr400265z| pmid = 24555663| title = Chromone: A Valid Scaffold in Medicinal Chemistry| journal = Chemical Reviews| volume = 114| issue = 9| pages = 4960–92| year = 2014| last1 = Gaspar | first1 = A. | last2 = Matos | first2 = M. J. O. | last3 = Garrido | first3 = J. | last4 = Uriarte | first4 = E. | last5 = Borges | first5 = F. | url = https://repositorio-aberto.up.pt/handle/10216/70808| url-access = subscription }} or coumarins{{Cite journal | doi = 10.1021/cr60113a001| title = The Chemistry of Coumarins| journal = Chemical Reviews| volume = 36| pages = 1–62| year = 1945| last1 = Sethna | first1 = S. M. | last2 = Shah | first2 = N. M. }} by acylation of O-hydroxyaryl ketones with aliphatic acid anhydrides, followed by cyclization.{{cite journal|doi=10.1002/cber.19010340119|title=Ueber eine Bildungsweise von Chromonderivaten|year=1901|last1=v. Kostanecki|first1=St.|last2=Różycki|first2=A.|journal=Berichte der Deutschen Chemischen Gesellschaft|volume=34|pages=102–109|url=https://zenodo.org/record/1426000}} If benzoic anhydride (or benzoyl chloride) is used, a particular type of chromone called a flavone is obtained. It was named after Polish chemist Stanisław Kostanecki.
Mechanism
The mechanism consists of three well-differentiated reactions:{{Cite journal |last1=Mamedov |first1=V. A. |last2=Kalinin |first2=A. A. |last3=Gubaidullin |first3=A. T. |last4=Litvinov |first4=I. A. |last5=Levin |first5=Ya. A. |date=2003 |title= 3-Benzoylquinoxalin-2(1H)-one in the Kostanecki-Robinson Reaction. Synthesis and Structure of 2-Oxo-4-phenylpyrano[2,3-b]quinoxaline |url=http://link.springer.com/10.1023/A:1023028927007 |journal=Chemistry of Heterocyclic Compounds |volume=39 |issue=1 |pages=96–100 |doi=10.1023/A:1023028927007|s2cid=98794444 |url-access=subscription }}Ellis, G. P. (1977) Chromenes, Chromanones, and Chromones from The Chemistry of Heterocyclic Compounds, Weissberger, A. and Taylor, E. C., eds.; Wiley & Sons: New York, vol. 31, p. 495.
- Phenol O-acylation with formation of a tetrahedral intermediate
- Intramolecular aldol condensation to cyclize and to form a hydroxydihydrochromone
- Elimination of the hydroxyl group to form the chromone (or coumarin)
