Kostanecki acylation

The Kostanecki acylation is a method used in organic synthesis to form chromones or coumarins by acylation of o-hydroxyaryl ketones with aliphatic acid anhydrides, followed by cyclization[1]:

Mechanism

The mechanism consists in three reactions well differenciated[2][3]:

1) Phenol O-Acylation with formation of a tetrahedrical intermediate.
2) Intramolecular aldolic condensation to cyclizate and to form a hydroxydihydrochromone.
3) Elimination of the hydroxyl group to form the chromone (or coumarin).

See also

References

  1. ^ S. von Kostanecki, A. Rozycki, Ber. 34, 102 (1901)
  2. ^ Mamedov, V. A.; Kalinin, A. A.; Gubaidullin, A. T.; Litvinov, I. A.; Levin, Ya. A.Chemistry of Heterocyclic Compounds 2003, 39, 96.
  3. ^ Ellis, G. P., Chromenes, Chromanones, and Chromones from The Chemistry of Heterocyclic Compounds, Weissberger, A. and Taylor, E. C., eds.; Wiley & Sons: New York, 1977, vol. 31, p.495. (Review).