tetrabutyl ammonium fluoride in tetrahydrofuran T=20°C; 1 h;

sodium hydroxide in ethanol T=50°C; 4 h;

1.1: n-BuLi / diethyl ether; hexane / 90 h / -78 - -40 °C 1.2: 80 percent / tetrahydrofuran; hexane / -78 - 20 °C 2.1: 75 percent / CuI; i-Pr2NH / bis(triphenylphosphine)palladium(II) chloride / tetrahydrofuran / Heating 3.1: 50 percent / NaOH / ethanol / 4 h / 50 °C View Scheme

1: 75 percent / CuI; i-Pr2NH / bis(triphenylphosphine)palladium(II) chloride / tetrahydrofuran / Heating 2: 50 percent / NaOH / ethanol / 4 h / 50 °C View Scheme