Hydrogen Peroxide → 4-Hydroxy-6-methyl-3-propargylsulfinyl-2-pyrone

Participants

Reaction Steps

To a suspension of 23.1 g. (0.124 mole) of 4-hydroxy-6-methyl-3-propargylthio-2-pyrone in 200 ml. of glacial acetic acid was added 14.1 g. (0.124 mole) of 30% hydrogen peroxide in 50 ml. of glacial acetic acid dropwise over a period of 20 minutes. The reaction mixture was stirred at room temperature for approximately 60 hours and then poured into 400 ml. of ice water. When no precipitate appeared, the solution was extracted with four 100 ml. portions of chloroform, and the extract was dried over anhydrous sodium sulfate. The chloroform was removed by evaporation in vacuo, leaving a solid residue and some acetic acid. The latter was removed by desiccation over sodium hydroxide at 0.2 mm. Hg. for four hours. The crude product was then recrystallized from ethanol, giving 17.7 g. (67 percent) of pale yellow crystals, m.p. 131°-134°C. A second recrystallization from ethanol gave the pure 4-hydroxy-6-methyl-3-propargylsulfinyl-2-pyrone as pale yellow needles, m.p. 133.5°-134.5°C.

Provenance & Evidence