反应详情

温度

65 °C

A solution of 6-acetyl-2,2-dimethylchroman (Compound 215, 2.15 g, 10.5 mmol) and NaOH (2.0 g, 50 mmol) in dioxane (50 mL) and bleach (50 mL, 5.25% NaOCl) was heated at 65° C. for 4 days. Upon cooling to room temperature Na2SO3 was added until an aliquot of this solution remained colorless color when treated with of one drop of a solution of I2 in CCl4. The solution was acidified with H2SO4 (pH 4) and extracted with ether. The combined organic layers were dried (Na2SO4) and concentrated under reduced pressure. Column chromatography (EtOAc:hexanes 1:3) afforded 1.98 g (92%) of 2,2-dimethylchroman-6-carboxylic acid as a light tan solid. 1H NMR δ 7.78 (2H, m), 6.82 (1H, d, J=8.3 Hz), 2.83 (2H, t, J=6.7, Hz), 1.85 (2H, t, J=6.7 Hz), 1.37 (6H, s).

1. additionwas added until an aliquot of this solution
2. extractionextracted with ether
3. dry with materialThe combined organic layers were dried (Na2SO4)
4. concentrationconcentrated under reduced pressure