1: 67 percent / triphenylphosphine, diethyl azodicarboxylate / tetrahydrofuran / 96 h / Ambient temperature 2: 95 percent / K2CO3 / methanol / 0.5 h / Ambient temperature 3: 68 percent / thiophenol, KOH / bis-(2-hydroxy-ethyl) ether / 0.5 h / 180 °C View Scheme