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Dimedone is an organic compound with the formula (CH3)2C(CH2)2(CO)2(CH2). Classified as a cyclic diketone, it is a derivative of 1,3-cyclohexanedione. It is a white solid that is soluble in water, as well as ethanol and methanol. It once was used as a reagent to test for the aldehyde functional group.

Synthesis

Dimedone is prepared from mesityl oxide and diethyl malonate via a Michael addition reaction.[1][2]

Chemical properties

Tautomerism

Dimedone is in equilibrium with its tautomer in solution — in a 2:1 keto to enol ratio in chloroform.[3]

Diagram of tautomeric equilibrium of dimedone

Crystalline dimedone contains chains of molecules, in the enol form, linked by hydrogen bonds:[4]

Ball-and-stick model of a hydrogen-bonded dimedone chain, as found in the crystal structure

Reaction with aldehydes

Dimedone reacts with aldehydes to give crystalline derivatives, whose melting points can be used to distinguish between aldehydes.[5]

Reaction of dimedone with formaldehyde

References

  1. ^ R. L. Shriner and H. R. Todd (1935). “5,5-dimethyl-1,3-cyclohexanedione”. Organic Syntheses. 15: 14. doi:10.15227/orgsyn.015.0014.
  2. ^ “Dimedone synthesis”. ChemTube3D. Retrieved 11 May 2023.
  3. ^ Clayden, Jonathan; Greeves, Nick; Warren, Stuart; Wothers, Peter (2001). Organic Chemistry (1st ed.). Oxford University Press. p. 530. ISBN 978-0-19-850346-0.
  4. ^ M. Bolte and M. Scholtyssik (October 1997). “Dimedone at 133K”. Acta Crystallogr. C. 53 (10): IUC9700013. Bibcode:1997AcCrC..53C0013B. doi:10.1107/S0108270197099423.
  5. ^ Horning, E. C.; Horning, M. G. (1946). “Methone Derivatives of Aldehydes”. The Journal of Organic Chemistry. 11 (1): 95–99. doi:10.1021/jo01171a014. ISSN 0022-3263. PMID 21013441.