Synthesis of Tanshinone IIA and Related Terpenes via a C–H Functionalization Strategy

The total synthesis of tanshinone IIA and related bioactive diterpenes isolated from the Chinese plant <i>Salvia miltiorrhiza</i> was completed from a common tetralin building block. The synthetic route highlights a 3,4-disubstituted furan synthesis and various regioselective C-H functionalization reactions, including a Pd catalyzed iodination and an Ir catalyzed borylation, along with an intramolecular stanna-Brook type reaction to construct the <i>ortho</i>-quninone ring of the target molecule.