1.1: i-PrMgCl; Ti(O-i-Pr)4 / diethyl ether / -78 - -50 °C 1.2: 88 percent / NBS / diethyl ether; tetrahydrofuran / -78 - 20 °C 2.1: 98 percent / imidazole / dimethylformamide / 20 °C 3.1: DBU / CH2Cl2 / 18 h / 20 °C 4.1: 1.32 g / Cs2CO3 / dimethylformamide / 20 h / 20 °C 5.1: aq. KOH; PdCl2(dppf) / tetrahydrofuran / 60 °C 6.1: TBAF / tetrahydrofuran / 20 °C View Scheme