反应详情

A solution of 5-methyl-3,6-dihydro-2H-pyran-2-carboxylic acid ethyl ester (140 mg, 0.823 mmol) in MeOH (3.5 mL) and 10% aq. NaOH (1.0 mL, 2.5 mmol) was heated at 65° C. for 3 h, reaction mixture was cooled to room temperature, solvent was evaporated, diluted with water. The aqueous solution was washed with ether, and acidified with aq. 1 N HCl, extracted with ether. The ethereal solution was washed with brine and dried. Evaporation of the solvent furnished 5-methyl-3,6-dihydro-2H-pyran-2-carboxylic acid (82 mg, 70% yield. NMR 1H (CDCl3, 400 MHz): 5.54-5.5 (m, 1H), 4.24-4.1 (m, 3H), 2.4-2.3 (m, 2H), 1.6 (s, 3H).

1. customreaction mixture
2. customsolvent was evaporated
3. additiondiluted with water
4. washThe aqueous solution was washed with ether
5. extractionextracted with ether
6. washThe ethereal solution was washed with brine
7. customdried
8. customEvaporation of the solvent