The stereocontrolled synthesis of the glutamate-containing natural product (S)-(+)-lycoperdic acid isdescribed. The key transformation in the synthetic route was an efficient diastereoselective annulation ofan oxolane ring onto a pyroglutamate scaffold to construct either a γ,γ-disubstituted glutamate-appendedtetrahydrofuran or a γ-lactone. The reaction sequence also featured an improved method for thehalogenation of pyroglutamate derivatives in high yield with enhanced stereoselection.