1: 87 percent / MeLi, CuCN / tetrahydrofuran / 0.5 h / -78 °C 2: 50 percent / DIBAL-H / diethyl ether / 1 h / -78 °C 3: 87 percent / i-Pr2EtN / CH2Cl2 / 12 h / Ambient temperature 4: 1.) aq. HCl, 2.) LiOH / 1.) THF, room temperature, 14 h, 2.) H2O, MeOH, room temperature, 10 h 5: 1.) Et3N, 2,4,6-trichlorobenzoyl chloride, 2.) N,N-dimethylaminopyridine / 1.) THF, room temperature, 6 h, 2.) toluene, reflux, 14 h 6: 85 percent / TiCl4 / CH2Cl2 / 2 h / 0 °C View Scheme