Baker–Venkataraman rearrangement

The Baker–Venkataraman rearrangement is the chemical reaction of 2-acetoxyacetophenones with base to form 1,3-diketones.[1][2]

This rearrangement reaction proceeds via enolate formation followed by acyl transfer. It is named after the scientists Wilson Baker and Krishnasami Venkataraman.

The Baker–Venkataraman rearrangement is often used to synthesize chromones and flavones.[3][4][5][6][7][8][9][10]

Contents

Mechanism

With a base being a catalyst, it attacks hydrogen atom in Acetophenone and an enolate is formed. Then, the enolate group attacks the carbon in the phenol ester to form a cyclic alkoxide. Finally, it opens up a phenolate which is reprocessed by acid to undergo protonation.

See also

References

  1. ^ Baker, W. (1933). "Molecular rearrangement of some o-acyloxyacetophenones and the mechanism of the production of 3-acylchromones". J. Chem. Soc.: 1381–1389. doi:10.1039/JR9330001381. 
  2. ^ Mahal, H. S.; Venkataraman, K. (1934). "Synthetical experiments in the chromone. group. XIV. Action of sodamide on 1-acyloxy-2-acetonaphthones". J. Chem. Soc.: 1767–1769. doi:10.1039/JR9340001767. 
  3. ^ T. S. Wheeler (1952). "Flavone". Organic Syntheses 32: 72. http://www.orgsyn.org/orgsyn/prep.asp?prep=cv4p0478.  (also in the Collective Volume (1963) 4:478 (PDF)).
  4. ^ Jain, P. K.; et al. (1982). "A Facile Baker-Venkataraman Synthesis of Flavones using Phase Transfer Catalysis". Synthesis 1982 (03): 221–222. doi:10.1055/s-1982-29755. 
  5. ^ Kalinin, A. V.;Da Silva, A. J. M.;Lopes, C. C.;Lopes, R. S. C.;Snieckus, V. (9 July 1998). "Directed ortho metalation - cross coupling links. Carbamoyl rendition of the baker-venkataraman rearrangement. Regiospecific route to substituted 4-hydroxycoumarins". Tetrahedron Lett. 39 (28): 4995–4998. doi:10.1016/S0040-4039(98)00977-0. 
  6. ^ Kraus, G. A.; Fulton, B. S. Wood, S.H.J.Org.Chem. 1984, 49, 3212
  7. ^ Reddy, B.P.; Krupadanam, G.L.D.J. Heterocycl. Chem 1996, 33, 1561
  8. ^ Kalinin, A.V.; Sneckus, V. Tetrahedron Lett. 1998, 39 4999
  9. ^ Thasana, N.; Ruchirawat, S. Tetrahedron Lett. 2002, 43, 4515
  10. ^ Santo, C.M.M.;Sliva, A.M.S. Cavaleiro, J. A.S. Eur.J. Org. Chem. 2003, 4575

External links