lactamlactones
Lactams are cyclic amides, and lactones are cyclic esters. Lactamlactones, also known as cyclic imides or imides, are organic compounds that contain both a lactam and a lactone functional group within the same molecule, or more accurately, are compounds containing two imide groups, each of which can be viewed as a cyclic amide. However, the term lactamlactone is sometimes used informally to describe molecules that incorporate both cyclic amide and cyclic ester functionalities in a fused or bridged ring system.
The most common interpretation of lactamlactone refers to compounds with two imide groups. These are formed
In a broader, less common interpretation, a molecule could be considered a lactamlactone if it contains both