2-oxoglutarate (OG)- and Fe(II)-dependent dioxygenase (2OGD) involved in scopoletin and umbelliferone biosynthesis (PubMed:22169019). Converts feruloyl CoA into 6'-hydroxyferuloyl CoA, and p-coumaroyl CoA into 2,4-dihydroxycinnamoyl-CoA, but has no activity with caffeoyl-CoA (PubMed:22169019). (E)-4-coumaroyl-CoA + 2-oxoglutarate + O2 = (E)-2,4-dihydroxycinnamoyl-CoA + CO2 + succinate (E)-feruloyl-CoA + 2-oxoglutarate + O2 = (E)-6-hydroxyferuloyl-CoA + CO2 + succinate Binds 1 Fe(2+) ion per subunit. kcat is 0.55 sec(-1) with feruloyl-CoA as substrate. kcat is 0.64 sec(-1) with p-Coumaroyl-CoA as substrate. Optimum pH is 7.2. Phenylpropanoid metabolism. Mostly expressed in underground stems and stems, and, at low levels, in tubers, leaves and petioles. Transiently induced by fungal (F.oxysporum f.sp. batatas O-17) and chitosan treatments, in association with the accumulation of umbelliferone and its glucoside (skimmin) in the tubers. Belongs to the iron/ascorbate-dependent oxidoreductase family.