1.1: aq. KOH / methanol / 12 h 2.1: 251 mg / [2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium]*BF4; (i-Pr)2NEt / CH2Cl2 / 12 h 3.1: BuLi / hexane; tetrahydrofuran / 0.25 h / -78 °C 3.2: 78 percent / hexane; tetrahydrofuran / -78 - 20 °C 4.1: 67 mg / acetonitrile / 2 h / Irradiation View Scheme

diisopropylamine; bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide in tetrahydrofuran Sonogashira coupling;

1.1: aq. KOH / methanol / 12 h 2.1: 251 mg / [2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium]*BF4; (i-Pr)2NEt / CH2Cl2 / 12 h 3.1: BuLi / hexane; tetrahydrofuran / 0.25 h / -78 °C 3.2: 78 percent / hexane; tetrahydrofuran / -78 - 20 °C View Scheme