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

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