)-ones I, compounds derived by cyclization of N
-acyl α-amino carboxylic acids, , through formal loss of the elements of water. 4-Hydrocarbylideneazlactones II are often referred to as 'unsaturated azlactones'.
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1321 (https://doi.org/10.1351/pac199567081307)