Phenylacetic Acid → (4S)-3-(2-Phenylacetyl)-4-(phenylmethyl)-2-oxazolidinone

Participants

Reaction Conditions

Reaction Steps

A solution of 10 gm of phenylacetic acid (73 mmol) and 12.2 mL of triethylamine (87.6 mmol) in 200 mL of THF was cooled to −78° C. To this solution was added 9.8 mL of trimethylacetyl chloride (80 mmol) and the reaction was warmed to 0° C. and stirred for 1 hr. This solution was recooled to −78° C. (Solution #1) Meanwhile, to a solution of 14.2 gm of (S)-(−)-4-benzyl-2-oxazolidinone in 200 mL of THF at −78° C., was added 50 mL of a 1.6M solution of n-butyl lithium in THF (80 mmol)over 20 min. (Solution #2) After stirring for 20 min., this solution (#2) was slowly cannulated into the solution (#1) containing the mixed anhydride at −78° C. This reaction mixture was allowed to warm to room temperature and stirred for 2 hr. The reaction was quenched with a solution of saturated NH4Cl and extracted with ethyl acetate. The combined organic fractions were washed with water, sat. NaHCO3 solution, sat. NaCl solution, dried over MgSO4, filtered and concentrated. The crude product was purified by chromatograpy (silica, hexanes:ethyl; acetate=4:1) to give the title compound.

Provenance & Evidence