1: With tris-trimethylsilyloxyethylene; Grubb's 2nd generation catalyst in dichloromethane 1.5 h; Heating; 2: With Grubb's 2nd generation catalyst in benzene 3 h; Heating;

bis(tricyclohexylphosphine)benzylidene ruthenium(IV) dichloride in dichloromethane T=50°C; 1 h;