Tamed cat: Iron-catalyzed selective C[BOND]H oxidation reactions present new possibilities in the synthesis and modification of natural products. As a model reaction of a possible C[BOND]H oxidation as part of a total synthesis, the natural product (+)-artemisinin was converted into (+)-10β-hydroxyartemisinin in 34 % yield (see scheme). The combination of nontoxic metal catalyst with H2O2 is an environmentally friendly process.