We report a simple, inexpensive, visual, and environmentally friendly S[subscript N]2 reaction appropriate for the second-year organic chemistry laboratory that illustrates stereospecificity, dependence of water solubility on the state of ionization, optical activity, and effect of diastereotopic protons in [superscript 1]H NMR spectroscopy. The reaction converts readily available l-phenylalanine in a double S[subscript N]2 reaction to enantiomerically pure ("S")-2-hydroxy-3-phenylpropanoic acid. The optical purity and absolute stereochemistry are determined by the specific rotation of the product. (Contains 1 figure, 1 scheme and 1 note.)