Potassium Carbonate → 6-ethynyl-3,4-dihydro-4,4-dimethylnaphthalen-1(2H)-one

Participants

Reaction Steps

To a solution (flushed for 15 minutes with a stream of argon) of 13.55 g (53.8 mmol) of 6-bromo-3,4-dihydro-4,4-dimethylnaphthalen-1(2H) -one (Compound H) in 280 ml of triethylamine was added 1.87 g (2.66 mmol) of bis(triphenylphosphine)palladium (II) chloride and 0.53 g (2.66 mmol) of cuprous iodide. The solution mixture was flushed with argon for 5 minutes and then 100 ml (938.7 mmol) of trimethylsilyl acetylene was added. The reaction mixture was sealed in a pressure tube and placed in a preheated oil bath (100° C.) for 24 hours. The reaction mixture was then filtered through Celite, washed with Et2O and the filtrate concentrated in vacuo to give crude 6-(2-trimethylsilyl)ethynyl-3,4-dihydro-4,4-dimethylnaphthalen-1(2H)-one. To a solution of this crude TMS-acetylenic compound in 50 ml of methanol was added 2.8 g (20.3 mmol) of K2CO3. The mixture was stirred for 8 hours at ambient temperature and then filtered. The filtrate was concentrated in vacuo, diluted with Et2O (100 ml), washed with water (10 ml), 10% HCl (10 ml) and brine (10 ml), dried over MgSO4 and concentrated in vacuo. Purification by column chromatography (silica, 10% EtOAc-hexane) yielded the title compound as a white solid.

Provenance & Evidence