[CH2:1]([O:3][C:4](=[O:13])[C:5]1[CH:10]=[C:9]([OH:11])[CH:8]=[C:7]([OH:12])[CH:6]=1)[CH3:2].C(=O)([O-])[O-].[K+].[K+].[CH2:20](Br)[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1.[K+].[Br-]>CC(C)=O>[CH2:1]([O:3][C:4](=[O:13])[C:5]1[CH:10]=[C:9]([O:11][CH2:20][C:21]2[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=2)[CH:8]=[C:7]([O:12][CH2:4][C:5]2[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=2)[CH:6]=1)[CH3:2]To a solution of ethyl-3,5-dihydroxy benzoate, 3 (16.8 g, 92 mmol) in acetone (350 mL) were added potassium carbonate (27.6 g, 200 mmol) and benzyl bromide (23.8 mL, 200 mmol) and stirred at room temperature for 9 h. Reaction mixture was filtered, concentrated on rotavapor and the crude product purified by column chromatography to afford 8. Yield 24.7 g (74%); mp 63-65° C.; MS (FAB) 363 (M++1); IR (KBr) 1824, 1708; 1H NMR (200 MHz, CDCl3) δ 7.34-7.35 (m, 10H), 7.30 (d, J=2.3 Hz, 2H), 6.79 (t, J=2.2 Hz, 1H), 5.07 (s, 4H), 4.36 (q, J=7.1 Hz, 2H), 1.38 (t, J=7.1 Hz, 3H).
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