Lactone vs. Lactam

Lactonenoun

(organic chemistry) A cyclic intramolecular ester derived from a hydroxy acid.

Lactonenoun

One of a series of organic compounds, being cyclic esters which may be regarded as anhydrides of certain hydroxy acids. In general, they are colorless liquids, having a weak aromatic odor. They are so called because the typical lactone is derived from lactic acid.

Lactone

Lactones are cyclic carboxylic esters, containing a 1-oxacycloalkan-2-one structure (−C(=O)−O−), or analogues having unsaturation or heteroatoms replacing one or more carbon atoms of the ring.Lactones are formed by intramolecular esterification of the corresponding hydroxycarboxylic acids, which takes place spontaneously when the ring that is formed is five- or six-membered. Lactones with three- or four-membered rings (α-lactones and β-lactones) are very reactive, making their isolation difficult.

Lactamnoun

(organic chemistry) Any of a class of cyclic amides that are the nitrogen analogs of lactones, formed by heating amino acids; the tautomeric enol forms are known as lactims.

Lactamnoun

One of a series of anhydrides of an amido type, analogous to the lactones, as oxindol; a cyclic amide.

Lactam

A lactam is a cyclic amide, formally derived from an amino alkanoic acid. The term is a portmanteau of the words lactone + amide.