Formal total synthesis of borrelidin: synthesis of C1–C11 fragment via desymmetrization strategy

A stereoselective formal total synthesis of borrelidin is described. The synthetic strategy for synthesis of C1–C11 fragment features desymmetrization of Diels–Alder adduct, Sharpless asymmetric epoxidation, regioselective opening of chiral epoxide, and alkylation using Evans chiral auxiliary.