triethylamine; sodium iodide in acetonitrile T=20°C; 4 h;

1.1: n-BuLi / tetrahydrofuran; hexane / 4 h / -78 °C 1.2: tetrahydrofuran; hexane / 11 h / -78 - 20 °C 2.1: 3.4 g / 2N HCl / tetrahydrofuran; hexane / 2 h / 20 °C 3.1: 88 percent / Et3N; NaI / acetonitrile / 4 h / 20 °C View Scheme