Chemistry experiments with an "element of discovery" are often more engaging for students than expository or "cookbook" versions where every student executes the same procedure and hopes for the same outcome. At Miami University Middletown, we've designed a discovery-based approach to an organic synthesis of phenyllactic acid from phenylalanine. Previously-published experiments focus on the elucidation of the reaction mechanism utilizing either the L- or D-phenylalanine reactant. In our version, students are given one of three unlabeled starting materials (L-phenylalanine, D-phenylalanine, or D,L-phenylalanine) and must deduce which form they receive based upon the characterization of their product. Students learn the importance of complementary analyses, coupled with an understanding of the reaction mechanism, as they solve their experimental puzzle. [ABSTRACT FROM AUTHOR]