[CH:1]([O:4][C:5]1[CH:6]=[C:7]([CH3:12])[CH:8]=[CH:9][C:10]=1Br)([CH3:3])[CH3:2].O1CCCC1.C([Li])CCC.[B:23](OCC)([O:27]CC)[O:24]CC>CCCCCC>[CH:1]([O:4][C:5]1[CH:6]=[C:7]([CH3:12])[CH:8]=[CH:9][C:10]=1[B:23]([OH:27])[OH:24])([CH3:3])[CH3:2]To a 125 mL 3N round-bottomed flask equipped with N2 inlet and septum were added 3.59 g (15.7 mmol) 3-isopropoxy-4-bromotoluene and 30 mL dry tetrahydrofuran. The solution was cooled to −70° C. and 7.5 mL (18.8 mmol) of a 2.5 M solution of butyl lithium in hexane was added over 5 minutes, and the solution stirred 5 minutes at −70° C. Then 3.2 mL (18.8 mmol) triethyl borate was added, followed by stirring for 5 minutes at −70° C. and then stirring at room temperature for 24 hours. The reaction was quenched with 1 N aqueous hydrochloric acid and extracted into ethyl acetate. The organic layer was washed with water and brine, dried over sodium sulfate, and evaporated. The residue was triturated with hexane to a white solid, 1.7 g (56%).
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