Boron trifluoride etherate → Methyl 4-(4-bromo-2,6-dimethylphenyl)-3-hydroxybutanoate

Participants

Reaction Steps

DIBAL-H (8.66 mL, 12.99 mmol) was added dropwise to a solution of methyl 2-(4-bromo-2,6-dimethylphenyl)acetate (3.18 g, 12.37 mmol) in CH2Cl2 (60 mL) at −78° C. and stirred for 1 h. 1-(tert-Butyldimethylsilyloxy)-1-methoxyethene (4.05 mL, 18.55 mmol) followed by BF3.OEt2 (1.959 mL, 15.46 mmol) were added. The reaction was stirred at −78° C. for 20 min and then allowed to warm to rt. The reaction was quenched by the addition of 10 mL of 1.0 M HCl, extracted with dichloromethane. The combined organics were washed with brine, dried over Na2SO4 and concentrated in vacuo. The crude product was purified by flash chromatography (loading in chloroform, 0% to 50% ethyl acetate in hexane over 15 min using a 40 g silica gel cartridge) to yield 2A (2.5 g, 8.30 mmol, 67.1% yield) as a clear oil. 1H NMR (500 MHz, chloroform-d) δ ppm 7.18 (2H, s), 4.20-4.28 (1H, m), 3.72 (3H, s), 2.91 (1H, dd, J=14.03, 8.25 Hz), 2.72-2.78 (2H, m), 2.53-2.57 (2H, m), 2.55 (2H, dd, J=40.03, 6.19 Hz), 2.33 (6H, s), 1.58 (2H, br. s.).

Provenance & Evidence