Previous studies on the influence of sterically non-interfering substituents on the optical stability of some 4-substituted N-benzenesulfonyl-N-car-boxymethyl-1-amino-2- methylnaphthalenes have shown that electron-withdrawing groups increase, whereas electron-donating groups decrease the racemization rate of the optically active compounds. The effect has been attributed to the degree of resonance stabilization of the planar ...