2-oxoglutarate + a (2R,3R)-dihydroflavonol + O2 = a flavonol + CO2 + H2O + succinate Binds 1 Fe(2+) ion per subunit. Secondary metabolite biosynthesis; flavonoid biosynthesis. A number of isoforms are produced. According to EST sequences. Expressed in young seedlings. No visible phenotype under normal growth conditions. Belongs to the iron/ascorbate-dependent oxidoreductase family.