1,2-Cyclopentanedione

1,2-Cyclopentanedione
Names
Preferred IUPAC name
Cyclopentane-1,2-dione
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.308.427 Edit this at Wikidata
UNII
  • InChI=1S/C5H6O2/c6-4-2-1-3-5(4)7/h1-3H2
    Key: CIISBNCSMVCNIP-UHFFFAOYSA-N
  • C1CC(=O)C(=O)C1
Properties
C5H6O2
Molar mass 98.101 g·mol−1
Appearance colorless liquid
Density 1.371 g/cm3
Melting point 56 °C (133 °F; 329 K)
Boiling point 87–88 °C (189–190 °F; 360–361 K) (15 mm Hg)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

1,2-Cyclopentanedione is the organic compound with the formula (CH2)3(CO)2. It is one of two isomeric cyclopentanediones, the other being 1,3-cyclopentanedione. It was first prepared by base-induced condensation of di ethylglutarate with diethyloxalate, followed by hydrolysis of the resulting diketodiester followed by decarboxylation.[1] The enol is predicted to be about 1-3 kcal/mol more stable than the diketo form.[2] The enol structure has been confirmed by X-ray crystallography.[3]

Structurally related to 1,2-cyclopentanedione is 2-hydroxy-3-methyl-2-cyclopenten-1-one is a flavor additive, also called cyclotene.

References

  1. ^ Hesse, Gerhard; Bücking, Eva (1949). "Die Synthese der Reduktinsäure (Synthesis of Reductic Acid)". Justus Liebigs Annalen der Chemie. 563: 31–37. doi:10.1002/jlac.19495630105.
  2. ^ Jana, Kalyanashis; Ganguly, Bishwajit (2018). "DFT Study to Explore the Importance of Ring Size and Effect of Solvents on the Keto–Enol Tautomerization Process of α- and β-Cyclodiones". ACS Omega. 3 (7): 8429–8439. doi:10.1021/acsomega.8b01008. PMC 6644555. PMID 31458971.
  3. ^ Gerrard, Juliet A.; Meade, Susie J.; Morris, Jonathan C.; Steel, Peter J. (2000). "Two crystalline modifications of 2-hydroxycyclopent-2-enone". Acta Crystallographica Section C: Crystal Structure Communications. 56 (10): 1251–1253. doi:10.1107/S0108270100009550. PMID 11025315.