Borane;tetrahydrofuran → (R)-Methyl 4-(4-fluorophenyl)-4-hydroxybutanoate

Participants

Reaction Steps

To a solution of BH3.THF (1M, 5.7 mL, 5.7 mmol) in 40 mL anhydrous THF was dropwise added at room temperature (S)-2-methyl-CBS-oxazaborolidine (952 μL, 0.952 mmol, 1M in toluene). After stirring for 5 minutes, methyl 4-(4-fluorophenyl)-4-oxobutanoate (2.0 g, 9.5 mmol) was added as a solution in 25 mL THF. The reaction mixture was stirred for 30 min at room temperature and then quenched by the slow addition of saturated aqueous ammonium chloride (60 mL) The resulting mixture was extracted with ethyl acetate (3×50 mL) and the combined organic layers washed with brine (2×40 mL) and dried over Na2SO4. The solvent was evaporated under reduced pressure and the product isolated by silica gel Flash chromatography to afford 1.7 g of the title compound as a colorless oil.

Provenance & Evidence