Cyclopentene is a chemical compound with the formula (CH2)3(CH)2. It is a colorless liquid with a petrol-like odor. It has few applications, and thus is mainly used as a minor component of gasoline, present in concentrations of less than 1%. It is one of the principal cycloalkenes.

History and synthesis

Cyclopentene was first prepared by Carl Gärtner in 1893 from iodocyclopentane with potassium hydroxide. He named it pentamethenylene (German:Pentamethenylen).

Cyclopentene is produced industrially in large amounts by steam cracking of naphtha. In the laboratory, it is prepared by dehydration of cyclopentanol. Substituted cyclopentenes are the product of the vinylcyclopropane-cyclopentene rearrangement.

It can also be produced by the catalytic hydrogenation of cyclopentadiene.

Reactions

The polymerization of cyclopentene by Ziegler-Natta catalysts yields 1,3-linkages, not the more typical 1,2-linked polymer.

Palladium-catalyzed hydrocarboxylation of cyclopentene gives cyclopentanecarboxylic acid:

C5H8 + CO + H2O → C5H9CO2H

External links

  • Media related toCyclopenteneat Wikimedia Commons