[CH3:1][O:2][C:3](=[O:15])[C:4]1[CH:9]=[C:8]([OH:10])[CH:7]=[C:6]([O:11][CH2:12][CH:13]=[CH2:14])[CH:5]=1.CI.[C:18]([O-])([O-])=O.[K+].[K+]>CN(C=O)C>[CH3:1][O:2][C:3](=[O:15])[C:4]1[CH:9]=[C:8]([O:10][CH3:18])[CH:7]=[C:6]([O:11][CH2:12][CH:13]=[CH2:14])[CH:5]=1To a solution of 3-allyloxy-5-hydroxy-benzoic acid methyl ester (la) (10.25 g, 49.2 mmol) in DMF (20 mL) was added methyl iodide (3.67 mL, 59.1 mmol) and K2CO3 (13.6 g, 98.5 mmol). The reaction mixture was stirred at 70° C. for 2 hr, cooled to room temperature. The mixture was quenched with H2O (150 mL) and extracted with EtOAc (2×150 mL). The organic layers were washed with H2O (2×150 mL), dried over MgSO4 and concentrated to give a pale yellow oil which was purified by flash column chromatography eluting with 10% EtOAc in hexane to give a colorless oil (9.63 g, 88% yield). 1H NMR (400 MHz, CDCl3) δ 7.11-7.24 (m, 2 H) 6.68 (t, J=2.40 Hz, 1 H) 5.91-6.17 (m, 1 H) 5.38-5.51 (m, 1 H) 5.31 (dd, J=10.48, 1.39 Hz, 1 H) 4.52-4.61 (m, 2 H) 3.91 (s, 3 H) 3.83 (s, 3 H); LCMS for C12H14O4 m/z 223.0 (M+H)+.
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