ketoses

Ketonic parent sugars (polyhydroxyketones H–[CHOH]n–C(=O)[CHOH]m–H with three or more carbon atoms) and their intramolecularhemiacetals. The oxo group is usually at C-2. E.g. d-fructose:
K03387
Source:
PAC, 1995, 67, 1307 (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1346
White Book, p. 129