[C:1]1([CH:8]=[CH:7][C:5]([OH:6])=[CH:4][CH:3]=1)[OH:2].[OH-].[K+].[Br:11][CH2:12][CH2:13][CH2:14]Br>CO>[Br:11][CH2:12][CH2:13][CH2:14][O:2][C:1]1[CH:8]=[CH:7][C:5]([OH:6])=[CH:4][CH:3]=1To a solution of hydroquinone (3.0 g, 27 mmol) in MeOH (30 mL), KOH (1.5 g, 27 mmol) was added. Then, 1,3-dibromopropane (3.3 mL, 32 mmol) was added dropwise over 10 minutes. After the addition was complete, the mixture was refluxed for 12 hours at 70° C. The reaction mixture was concentrated and quenched with water (100 mL), and then the aqueous layer was extracted with EtOAc (2×50 mL). The combined organic layer was with washed water, thetn brine, and dried over Na2SO4. The solvent was evaporated and the product was purified by column chromatography to isolate the intermediate 10a (1.46 g, 6.31 mmol, 23% yield) as a pinkish solid. 1H NMR (CDCl3, 400 MHz) δ 6.81 (m, 4H), 5.93 (broad s, 1H), 4.06 (t, 2H), 3.61 (t, 2H), 2.30 (m, 2H).
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