Cyclopropane

Cyclopropane is a cycloalkane molecule with the molecular formula C₃H₆ consisting of three carbon atoms linked to each other to form a ring, with each carbon atom bearing two hydrogen atoms. The bonds between the carbon atoms are a great deal weaker than in a typical carbon-carbon bond, making the resultant compound more reactive than acyclic alkanes and other cycloalkanes such as cyclohexane and cyclopentane.

Boiling point: -32.8°C Freezing point: -127°C

The naturally ocurring pyrethrum insecticides (found in certain Chrysanthemum species) contain a cyclopropane ring.