Mild Friedel-Crafts Reactions Enable a Robust Synthesis of Roseophilin.

An 11-step total synthesis of either enantiomer of roseophilin has been developed. The chemistry features effective production of a challenging carbocation on a macrocyclic segment 25 and a highly efficient intermolecular Friedel-Crafts alkylation reaction to integrate a complex furan-pyrrole unit 5 regioselectively with this carbocation under very mild reaction conditions.