https://doi.org/10.1351/goldbook.G02665
The structure obtained by removing the hydroxy group from the @H02774@ function of a @M04021@ and, by extension, of a lower @O04289@.
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1338 [Terms] [Paper]