Cyclopropanes are a family of organic compounds containing the cyclopropyl group. The parent is cyclopropane .
Most cyclopropanes are not prepared from the parent cyclopropane, which is somewhat inert.Cyclopropyl groups are often prepared by cyclization of 1,3-difunctional alkanes. An example of the former, cyclopropyl cyanide is prepared by the reaction of 4-chlorobutyronitrile with a strong base.[1] Phenylcyclopropane is produced analogously from the 1,3-dibromide.[2]
A second major route to cyclopropanes entails addition of methylene (or its substituted derivatives) to an alkene, a process called cyclopropanation.[3]
Substituted cyclopropanes undergo the reactions associated with the cyclopropyl ring or the substituents. Vinylcyclopropanes are a special case as they undergo vinylcyclopropane rearrangement.
Cyclopropane derivatives are numerous.[4] Many biomolecules and pharmaceutical drugs feature the cyclopropane ring. Famous example is aminocyclopropane carboxylic acid, which is the precursor to ethylene, a plant hormone.[5]
The pyrethroids are the basis of many insecticides.[6] Several cyclopropane fatty acids are known.
thumb|left|122 px|1-Aminocyclopropane-1-carboxylic acid plays an important role in the biosynthesis of the plant hormone ethylene.