1: 54 percent / tri-2-furylphosphine; CuI; Pd2(dba)3 / Bu4NCl / dimethylformamide / 2 h / 20 °C 2: TBAF; AcOH / tetrahydrofuran / 5 h / 20 °C 3: IBX / ethyl acetate / 2 h / 80 °C 4: 28.4 mg / 2-methyl-2-butene; NaH2PO4*H2O; NaClO2 / 2-methyl-propan-2-ol; tetrahydrofuran; H2O / 0.5 h / 20 °C View Scheme

1: 54 percent / tri-2-furylphosphine; CuI; Pd2(dba)3 / Bu4NCl / dimethylformamide / 2 h / 20 °C 2: TBAF; AcOH / tetrahydrofuran / 5 h / 20 °C 3: IBX / ethyl acetate / 2 h / 80 °C View Scheme