Br[C:2]1[CH:7]=[C:6]([CH3:8])[CH:5]=[CH:4][C:3]=1[C:9]1([O:14]COC)[CH2:13][CH2:12][CH2:11][CH2:10]1.[Li]CCCC.[B:23](OC(C)C)(OC(C)C)[O:24]C(C)C>C1COCC1>[CH3:8][C:6]1[CH:5]=[CH:4][C:3]2[C:9]3([CH2:13][CH2:12][CH2:11][CH2:10]3)[O:14][B:23]([OH:24])[C:2]=2[CH:7]=1To a solution of 2-bromo-1-(1-(methoxymethoxy)cyclopentyl)-4-methylbenzene (2.2 g, 714 mmol) in THF (40 mL) at −78° C. was added n-BuLi (7.5 mL, 18.5 mmol) dropwise. The mixture was stirred at −78° C. for additional 1 h and then triisopropyl borate (2.8 g, 14.8 mmol) in 10 mL of THF was added below −70° C. The resulting mixture was kept stirring at −78° C. for 30 min and allowed to warm to rt and stirred overnight. Then it was quenched with aqueous NH4Cl and extracted with ethyl acetate. The organic layer was dried over Na2SO4 and concentrated under reduced pressure. The residue was purified on column chromatography to provide the product (1.2 g, yield 81%).
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