Quinone → 2,5-Cyclohexadien-1-one, 4-hydroxy-4-(phenylethynyl)-

Participants

Reaction Conditions

Reaction Steps

A suspension of potassium bis(trimethylsilyl)amide (1.95 g, 0.0098 mole) in 20 mL of dry THF was treated with phenylacetylene (0.92 g, 0.009 mole). A flocculant white precipitate formed immediately. Benzoquinone (0.97 g, 0.009 mole) was dissolved in dry THF (10 mL) and cooled to -78° C. The potassium phenylacetylide generated above was added dropwise over a period of about 10 min. The reaction was stirred an additional 10 min, quenched by adding saturated ammonium chloride solution (20 mL) and allowed to warm to RT. The mixture was diluted with saturated ammonium chloride solution, extracted with ether and filtered to remove a flocculant dark brown precipitate. The phases were separated and the aqueous phase extracted with additional ether. The combined ether extracts were dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flask chromatography on silica gel using 4:1 hexane/EtOAc as the eluent and the fractions containing the title product were combined and concentrated in vacuo to yield 0.27 g (14%).

Provenance & Evidence