present a full account on the development of the totalsynthesis of the antiviral meroterpenoid (+)-stachyflin. The decalin subunit is rapidly accessed by an exo-selective Diels–Alder reaction, whereas the isonindolinone was synthesized via a highly efficient and practical de novo route starting from dimedone. A challenging sp2–sp3 Negishicross-couplingreaction enabled construction of the crucial C15–C16