1.1: Cp2Zr(H)Cl / tetrahydrofuran / 0.67 h / 0 °C 1.2: ZnCl2 / tetrahydrofuran / 0.17 h / 0 °C 1.3: 80 percent / Pd(PPh3)4 / tetrahydrofuran / 0.83 h / 0 - 20 °C 2.1: Me3P / tetrahydrofuran / 4 h / 20 °C 2.2: H2O / tetrahydrofuran / 1.5 h / 20 °C 3.1: 30.4 mg / DIPEA; HATU / acetonitrile / 0.5 h / 20 °C 4.1: DBU / dimethylformamide / 60 h / 20 °C 5.1: 16.2 mg / TBAF; AcOH / tetrahydrofuran / 0.25 h / 0 °C 6.1: TsOH*H2O / tetrahydrofuran; H2O / 2 h / 20 °C View Scheme