1.1: 95 percent / 1,8-diazabicyclo[5.4.0]undec-7-ene / tetrahydrofuran / cooling 2.1: trifluoroacetic acid / methanol / cooling 2.2: 89 percent / triethylamine; 4-(dimethylamino)pyridine / tetrahydrofuran / cooling 3.1: 21 percent / (1,3-dimesitylimidazolidin-2-yl)(P(c-Hex)3)(Cl)2Ru=CHC6H5 / CH2Cl2 / 16 h / Heating 4.1: 76 percent / cerium(III) chloride heptahydrate; sodium borohydride / methanol / 3 h / 0 °C View Scheme