Hydrochloric Acid → (+)-(S)-2-methyl-3-(pent-4-en-2-ynyl)-cyclopent-2-en-4-one-1-ol

Participants

Reaction Steps

10 Grams of (+)-(S)-2-methyl-3-propargylcyclopent-2-en-4-one-1-ol was dissolved in 100 ml of benzene. Thereto were added successively 3.85 g of tetrakis(triphenylphosphine)palladium, 1.27 g of cuprous iodide and 13.5 g of triethylamine. 150 Grams of vinyl bromide was promptly added to the resultant mixture. The mixture was stirred under nitrogen atmosphere at room temperature overnight. Thereafter, the mixture was poured on dilute hydrochloric acid. A benzene layer was recovered from the mixture, and the water layer was further extracted with benzene. The benzene layers were mixed, washed with saturated brine, and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure. Methanol was added to the residue, and insolubles were removed by filtration. The filtrate was concentrated under reduced pressure, and the residue was subjected to silica gel column chromatography (elution solvent; hexane:ethyl acetate=3:1) to obtain 7.5 g of (+)-(S)-2-methyl-3-(pent-4-en-2-ynyl)-cyclopent-2-en-4-one-1-ol.

Provenance & Evidence