Sulfuric Acid → 3-(1-Adamantylthio)-4-hydroxy-6-methyl-2-pyrone

Participants

Reaction Steps

Ice (22 g.) was slowly added to 90 g. of concd. sulfuric acid with stirring, keeping the temperature below 35°C. by means of an ice-salt bath. 1-Adamantanol (18.2 g., 0.120 mole) was added followed by the slow addition of 15.8 g. (0.100 mole) of 4-hydroxy-3-mercapto-6-methyl-2-pyrone, keeping the temperature of the reaction mixture between 0° and 5°C. The ice bath was then removed from the reaction vessel, and the reaction mixture was warmed to 30°-40°C. with vigorous stirring for 1.5 hours. The mixture was then poured into ice water and allowed to stand for about 15 hours. The crude, solid product was collected on a filter, dried in vacuo over calcium chloride and recrystallized from ethanol (Darco) to give 8.3 g. (28 percent) of colorless needles, m.p. 175.5°-176.5°C. A second recrystallization from ethanol gave the pure product as colorless needles, m.p. 176°-177°C.

Provenance & Evidence