1,2-Cyclopentanedione is the

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon- hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. Th ...

with the formula (CH₂)₃(CO)₂. It is one of two isomeric cyclopentanediones, the other being

1,3-cyclopentanedione 1,3-Cyclopentanedione is an organic compound with the formula (CH2)3(CO)2. It is one of two isomeric cyclopentanediones, the other being 1,2-cyclopentanedione. The enol is predicted to be about 1-3 kcal/mol more stable than the diketo form. The ...

. It was first prepared by base-induced condensation of di ethylglutarate with diethyloxalate, followed by hydrolysis of the resulting diketodiester followed by decarboxylation. The

enol In organic chemistry, alkenols (shortened to enols) are a type of reactive structure or intermediate in organic chemistry that is represented as an alkene (olefin) with a hydroxyl group attached to one end of the alkene double bond (). The te ...

is predicted to be about 1-3 kcal/mol more stable than the diketo form. The enol structure has been confirmed by

X-ray crystallography X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angle ...

. Structurally related to 1,2-cyclopentanedione is

2-hydroxy-3-methyl-2-cyclopenten-1-one 2-Hydroxy-3-methyl-2-cyclopenten-1-one is an organic compound related to 1,2-cyclopentanedione. It is the enol tautomer of the diketone 3-methylcyclopentane-1,2-dione. Being an enol, the compound is often called methylcyclopentenolone. It is a ...

is a flavor additive, also called cyclotene.

References

{{DEFAULTSORT:Cyclopentanedione, 1, 2- Diketones Cyclic ketones