1.1: 88 percent / DIBAL-H / CH2Cl2 / 2 h / 0 °C 2.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 3 h / 0 °C 2.2: 90 percent / DMAP / toluene / 1 h / 20 °C 3.1: 35 percent / 1,3-bis(mesityl)imidazolidin-2-yl[Cl2Ru(PCy3)=CHPh] / toluene / 20 h / 90 °C 4.1: 95 percent / TFA / CH2Cl2 / 1 h / 20 °C 5.1: 80 percent / DIC; DMAP / 12 h / 0 °C 6.1: 90 percent / TiCl4 / CH2Cl2 / 0.5 h / 0 °C View Scheme

Multi-step reaction with 2 steps 1: phosphorus tribromide / diethyl ether / 2 h / 0 °C2: sodium hydride; tetra-(n-butyl)ammonium iodide / tetrahydrofuran; mineral oil / 0 - 23 °C / |Inert atmosphere