hemiketals

https://doi.org/10.1351/goldbook.H02776
hemiacetals having the structure R2C(OH)OR (RH), derived from ketones by formal addition of an alcohol to the carbonyl group. This term, once abandoned, has been reinstated as a subclass of hemiacetals.
Source:
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1339 (https://doi.org/10.1351/pac199567081307)