1: 78 percent / tetrahydrofuran; diethyl ether / 1) 0 deg C, 1 h, 2) 20 deg C, 16 h 2: 61 percent / 1,3,5-trimethyl-benzene / 16 h / 165 °C 3: 42 percent / KOH / H2O / 4 h / Heating View Scheme