ethyl 3,4-dihydro-1H-2-benzopyran-1-acetate → 2-(3,4-dihydro-1H-2-benzopyran-1-yl)acetic acid

反応式

C([O:3][C:4](=[O:16])[CH2:5][CH:6]1[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[CH2:9][CH2:8][O:7]1)C>C1COCC1.CO.[OH-].[Na+]>[CH:6]1([CH2:5][C:4]([OH:16])=[O:3])[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[CH2:9][CH2:8][O:7]1

参加物

実験手順

To a solution of (±)-isochroman-1-yl-acetic acid ethyl ester (1.90 g, 8.63 mmol, 1 eq.) in THF (40 mL) and MeOH (10 mL), 1M aq. NaOH soln. (17.3 mL, 17.3 mmol, 2 eq.) was added. The pale yellow solution was stirred at r.t. for 2 hours, then the organic solvents were removed in vacuo. The aq. layer was washed with AcOEt (1×10 mL). The aq. layer was acidified with 1N aq. HCl (pH=1). The resulting emulsion was extracted with DCM (3×25 mL). The comb. org. phases were dried over MgSO4 and concentrated in vacuo to give the title compound as a colorless oil that solidifies upon standing. The product was used without further purification.