Hydrogen Peroxide → (R)-2-(biphenyl-4-ylmethyl)-4-tert-butoxy-4-oxobutanoic acid

Beteiligte Stoffe

Reaktionsschritte

To a stirred solution of (R)-tert-butyl 4-((S)-4-benzyl-2-oxooxazolidin-3-yl)-3-(biphenyl-4-ylmethyl)-4-oxobutanoate (1.20 g, 2.402 mmol) in a mixed solvent of THF (20 mL) and water (5 mL), a solution of aqueous H2O2 (0.960 mL, 9.61 mmol) and aqueous LiOH (4.80 ml, 4.80 mmol) is added at 0° C. during 5 minutes. After stirring for 1.5 hour, the reaction is quenched with saturated aqueous Na2SO3 (10 mL) at 0° C., and allowed to stir for 10 minutes at the same temperature. The reaction mixture is warmed up to ambient temperature while stirring for 0.5 hour. Then, saturated aqueous NaHCO3 and brine are added to the mixture. The product is extracted with ethyl acetate, washed with aqueous 1M HCl, dried over MgSO4, filtered, and concentrated under reduced pressure. The obtained residue is purified by flash column chromatography on 120 g of silica gel (heptane/EtOAc=75:25 to 0:100) to give (R)-2-(biphenyl-4-ylmethyl)-4-tert-butoxy-4-oxobutanoic acid (765 mg, 93%). HPLC retention time=1.63 minutes (condition D); MS=338.6 (m−1); 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.43 (s, 9 H) 2.41 (A of ABX, Jab=16.67 Hz, Jax=4.55 Hz, 1 H) 2.52-2.67 (B of ABX, Jab=16.75 Hz, Jbx=8.45 Hz, 1 H) 2.74-2.89 (m, 1 H) 3.06-3.22 (m, 2 H) 7.22-7.29 (m, 2 H) 7.30-7.37 (m, 1 H) 7.43 (t, J=7.58 Hz, 2 H) 7.53 (d, J=8.1 Hz, 2 H) 7.57 (d, J=7.8 Hz, 2 H).

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