Water → 7-hydroxy-2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-4-one

Participants

Reaction Conditions

Reaction Steps

In a flask were placed 55.1 grams (0.5 mole) of resorcinol and 55.1 grams (0.5 mole) 3,3-dimethylacrylic acid. Then, 150 grams of polyphosphoric acid was added, and a steam bath applied to the flask. A red liquid began to form; the temperature of the reaction mixture quickly rose to 120° C. The flask was stirred for 45 minutes at 110° C., then allowed to cool. The contents were poured into a mixture of 500 milliliters water and 400 milliliters methylene chloride then stirred and filtered. The precipitate was washed several times with portions of methylene chloride, water and toluene. There was obtained 65.8 grams, (68% of theoretical yield) 2,2-dimethyl-7-hydroxy-4-chromanone, m.p. 170°-174° C.

Provenance & Evidence