反应详情

温度

55 °C

To a stirred solution of dihydrocoumarin (10 mL, 78.9 mmol) and a catalytic amount of conc. H2SO4 in dry methanol (300 mL) was added and the reaction mixture was then heated at 55° C. for 8 hours. Methanol was evaporated to dryness to give crude product which was subjected to neutralize with K2CO3. The residue was diluted with water and extracted with dichloromethane. Purification of the crude product by column chromatography (20% CH2Cl2:3% EtOAc:77% Hexane as eluent) gave the desired ester as colorless oil (12.80 g, 90%). 1H NMR (400 MHz, CDCl3): 2.71 (3H, t, J=6.4 Hz), 2.89 (2H, t, J=6.4 Hz), 3.67 (3H, s), 6.83-6.87 (2H, m), 7.06-7.12 (2H, m),

1. customMethanol was evaporated to dryness
2. customto give crude product which
3. extractionextracted with dichloromethane
4. customPurification of the crude product by column chromatography (20% CH2Cl2:3% EtOAc:77% Hexane as eluent)