A mixture of 1.68 g (5.38 mmol) of 6-bromo-4,4-dibutylthiochroman (Compound 33), 0.28 g (1.5 mmol) of copper (I) iodide and 2.5 g (25 mmol) of triethylamine was degassed with argon for 15 minutes at -78° C. To the suspension was added 1.18 g (71 mmol) of (trimethylsilyl)acetylene and 0.24 g (0.3 mmol) of bis(triphenylphosphine)palladium (II) chloride. The solution was degassed with argon for an additional 5 minutes and the resulting mixture was allowed to warm to 0° C. The tube was sealed and the mixture was heated to 55° C. for 22 hours.
