Illustrated Glossary of Organic Chemistry

Lactone: An ester contained within a ring. Shown below are sample lactones, with the lactone moieties in red.




Nepetalactone
The cat attractant/stimulant found in catnip.
Contains a six-membered lactone.
  
Xenical (orlistat)
A weight control drug.
Contains a four-membered lactone.