Catalyzes the Fe(2+) and alpha-ketoglutarate-dependent oxidation of pentalenolactone D to pentalenolactone F in the biosynthesis of pentalenolactone antibiotic. Also able to catalyze the oxidation of pentalenolactone D to pentalenolactone E. 2 2-oxoglutarate + 2 O2 + pentalenolactone D = 2 CO2 + H2O + pentalenolactone F + 2 succinate Binds 1 Fe(2+) ion per subunit. Activated by ascorbate. Antibiotic biosynthesis; pentalenolactone biosynthesis. Accumulation of pentalenolactone D and lack of production of pentalenolactone as well as the precursors pentalenolactones E and F. Belongs to the TfdA dioxygenase family.