A simplified procedure for the N-acylation of oxazolidin-2-one chiral auxiliaries has been developed. The acylations occur at room temperature in the presence of triethylamine and catalytic quantities of 4-(N,N-dimethylamino)pyridine, thereby eliminating the necessity for a strong base such as butyllithium. Acylations with both symmetrical and mixed anhydrides, as well as acid chlorides, occur with a wide variety of oxazolidinone auxiliaries.