A degassed mixture of 4-bromo-1-[6-(tetrahydropyran-2-yloxy)hexyloxy]benzene (20 g), 2-methyl-3-butyn-2-ol (18.85 g), triphenylphosphine (TPP, 0.59 g), copper (I) iodide (0.11 g) and bis(triphenylphosphine)palladium dichloride (0.40 g) in 200 ml of triethylamine was refluxed for 4 hours under an atmosphere of argon. After being cooled the reaction mixture was filtered over celite to give a yellowish solution which was evaporated to dryness. The resulting yellow oil was dissolved in 200 ml of a toluene/triethylamine mixture (1:1) to which 14.45 g of KOH was then added. The resulting mixture was heated at reflux for 12 h, cooled and filtered over 260 g of silica gel using diethylether as eluent. This yields a dark oil which was purified by chromatography using a silica gel clolumn and cyclohexane/ethyl acetate (9:1) as eluent to give 12.28 g of 4-[6-(tetrahydropyran-2-yloxy)hexyloxy]phenylacetylene as a red oil.
