Dimedone

Dimedone
IUPAC name 5,5-Dimethylcyclohexane-1,3-dione
Other names Cyclomethone, 5,5-dimethyl-1,3-cyclohexanedione, Dimethyldihydroresorcinol, Methone
Identifiers
CAS number	126-81-8 Y
PubChem	31358
ChemSpider	29091 Y
Jmol-3D images	Image 1
SMILES O=C1CC(=O)CC(C)(C)C1
InChI InChI=1S/C8H12O2/c1-8(2)4-6(9)3-7(10)5-8/h3-5H2,1-2H3 Y Key: BADXJIPKFRBFOT-UHFFFAOYSA-N Y InChI=1/C8H12O2/c1-8(2)4-6(9)3-7(10)5-8/h3-5H2,1-2H3 Key: BADXJIPKFRBFOT-UHFFFAOYAX
Properties
Molecular formula	C8H12O2
Molar mass	140.17968
Appearance	Yellow crystals
Melting point	147-150 °C (decomposes)
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Dimedone is a cyclic diketone used in organic chemistry to determine whether a compound contains an aldehyde group. Cyclohexanediones in general can be used as catalysts in the formation of transition-metal complexes. Other uses include applications in colourimetry, crystallography, luminescence and spectrophotometric analysis. It can also be used for chemistry involving organic compounds of low electrical resistance.

Synthesis

Dimedone is prepared from mesityl oxide and diethyl malonate^[1].

Physical properties

Dimedone usually comes in the form of yellow crystals. It is stable under ambient conditions and soluble in water, as well as ethanol and methanol. It has a melting point range of 147 - 150 °C (420 - 423 K).

Tautomerism

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

Crystalline dimedone contains chains of molecules, in the enol form, linked by hydrogen bonds^[3]:

References

1. ^ R. L. Shriner and H. R. Todd (1935). "5,5-dimethyl-1,3-cyclohexanedione". Organic Syntheses 15: 16. http://www.orgsyn.org/orgsyn/prep.asp?prep=cv2p0200. 
2. ^ Clayden, Jonathan; Greeves, Nick; Warren, Stuart; Wothers, Peter (2001). Organic Chemistry (1st ed.). Oxford University Press. pp. p. 532. ISBN 978-0-19-850346-0. 
3. ^ M. Bolte and M. Scholtyssik (October 1997). "Dimedone at 133K". Acta Cryst. C53 (10): IUC9700013. doi:10.1107/S0108270197099423.