1.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -78 °C 1.2: 76 percent / tetrahydrofuran; hexane / 16 h / -78 - 20 °C 2.1: 63 percent / Grubbs second generation catalyst / CH2Cl2 / 0.25 h / 140 °C / microwave irradiation 3.1: TFA; water / acetonitrile / 0.33 h / 60 °C / microwave irradiation View Scheme

1.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -78 °C 1.2: 76 percent / tetrahydrofuran; hexane / 16 h / -78 - 20 °C 2.1: 63 percent / Grubbs second generation catalyst / CH2Cl2 / 0.25 h / 140 °C / microwave irradiation 3.1: TFA; water / acetonitrile / 0.33 h / 60 °C / microwave irradiation 4.1: 0.56 g / tetrahydrofuran / 20 h / Heating View Scheme