platinum (II) chloride in toluene T=60 - 80°C;

1.1: n-BuLi / tetrahydrofuran; hexane / 0.25 h / -78 °C 1.2: 43 percent / HMPA / tetrahydrofuran; hexane / -78 - 20 °C 2.1: 62 percent / PtCl2 / toluene / 60 - 80 °C View Scheme

silica gel T=70°C; 3 h;

hydrogenchloride 1) MeCN, 3 h, 70 deg C, 2) aq. acetone, reflux; Yield given. Multistep reaction. Yields of byproduct given;