Sulfuric Acid → 3,4-Dihydro-6-hydroxy-2,5,7,8-tetramethyl-2H-1-benzopyran-2-carbonitrile

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Reaction Steps

A solution of 5.31 g. of (±)-2-cyano-4-(5-acetoxy-2-hydroxy-3,4,6-trimethylphenyl)butan-2-ol in 60 ml. of methanol was cooled in an ice bath under N2. Sulfuric acid (3.8 ml.) was added over 5 minutes. The light yellow solution was stirred at 23° for 72 hours and then at reflux for 5 hours, cooled, poured into ice-H2O and filtered. The solid was washed with H2O and crystallized from ether-30°-60° petroleum ether to give (±)-2-cyano-6-hydroxy-2,5,7,8-tetramethylchroman as a white needle, m.p. 152.5°-153° .

Provenance & Evidence