monosahhariidid, milles ketorühma ja karboksüülhappe rühma sisaldav struktuur on tasakaalus poolatsetaalse struktuuriga, sel puhul kasutatakse sufiksit -ulosoonhape, monosaccharides in which a structure containing a keto group and a carboxylic acid group is in equilibrium with a hemiacetal structure. Specific compounds are named using the -ulosonic acid suffix