1: 94 percent / Et3N / (Ph3P)2PdCl2 / 75 °C 2: H2, Lindlar catalyst, quinoline / hexane 3: 2,2,4-trimethyl-pentane / Heating 4: 82 percent / ion-exchange resin AG 50W-X4 / methanol / 48 h / Ambient temperature; in the dark View Scheme