1: 78 percent / n-BuLi / tetrahydrofuran; hexane / 7 h / -78 - 20 °C 2: 81 percent / NaI, trimethylsilyl chloride / acetonitrile / 3 h / Ambient temperature View Scheme

Multi-step reaction with 2 steps 1: 83 percent / DBU / tetrahydrofuran / 4 h / Ambient temperature2: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) 0 deg C, 3 h