A New Approach to Organic Laboratory Projects Individualized projects in the laboratory result in greater student enthusiasm, develop self-confidence, and pmvide a greater variety of experience than do the more common experiments found in laboratory manuals. In addition, experiments utilizing compounds that are involved in biochemical processes have become increasingly desirable with the expanding enrollments of students interested in medically-oriented fields. For the past two years we have devoted up to fifty student laboratory hours in the second semester of the organic chemistry lahoratory to individualized student projects involving steroids. The steroid field is well-suited to such experimentation because of the volume of information known concerning the characterization and reactions of the individual steroid compounds and because many reactions with stemids are selective and occur in high yields. In addition, because steroids are complex biochemically-related compounds, successful experiments heighten student enthusiasm and self-confidence and provide a greater familiarity with chemical reactions and techniques. During the past year we initiated a program designed to synthesize the proposed hut elusive human sex attractant in the time alloted to individual student projects. Literature notations to the peculiar odor characteristics of known AlK-nndrosreneu and suggestruns of prnons familiar with phermone research led us to artempr the synthese of varnus A1"andrwrene dwiratiws in the beliet that one of these derivnt!res might he a marnmal~anphemone. 'l'he propoard >I6-andrmt~ne derwntires ~nrludedthe 3-01, R-one. : i . ; l - d ~ Land :(-one-5-01in d~ffermp.stereochemical ronfonnations at the 3- and 5-positions; only two of these compounds had been previously reported i n t h e literature. Students worked in pairs, and each pair was assigned the synthesis of one of the proposed structures and was expected to devise a reasonable synthetic scheme from the literature using either A4-androstene-3~-ol-ll-one or testosterone as a starting material. Proposed syntheses (requiring from five to eight steps) that included precise experimental procedures and references to analogous reactions from the literature, were submitted to the instructor for approval and refinement. Since most syntheses involved classical experiments, there were a minimum of rejections for procedures based an the unavailability of equipment or chemicals. The syntheses attempted involved catalytic hydrogenation, metal hydride reductions, Wolff-Kishner reduetions, peroxidations, the use of protective groups (tosylation, ketal formation), elimination reactions, and a variety of reactions specific to individual compounds. In addition to the exacting literature search that in mast cases involved the proposal of a stereoselective synthesis, students utilized pmr and ir spectroscopy, the polmimeter, various methods of catalytic hydrogenation and a variety of purification methods. Fmnal reports from eaehgroup were ahtained after completion of the experiments. The use of such independent student projects in the organic chemistry laboratory has provided a better understanding of chemical reactions and techniques and has allowed students to experience the rewards and frustrations of research. Familiarity with the projects of other groups expands student laboratory experience and similates a team effort. Students beginning research projects with faculty members after this lahoratory have been able to adjust in less time to the requirements of the specific project. Student evaluations have been unanimous in support of individual projects, even though more time and effort is involved. Although not all groups completed their syntheses in the time alloted, the groups that were successful could perceive the unexpected odor characteristics of several A16-androstenes. During the experimentation we had observed no noticeable increase in pugnacity that had been attributed to testasterone in the literature and, in completing these student projects during the spring observed no student behavior that was unexpected. Michael P. Doyle William S. Mungall Hope College Holland, Michigan 49423
358 /Journal of Chemical Education
