This laboratory experiment provides a unique opportunity for students to synthesize three analogues of aspartame, a commonly used artificial sweetener. The students are introduced to the powerful and useful method of parallel synthesis while synthesizing three dipeptides in parallel using solid-phase peptide synthesis (SPPS) and simultaneous multiple parallel synthesis (SMPS) methodologies. They are introduced to new concepts such as protecting groups and coupling agents and they use purification by high-pressure liquid chromatography and characterization by thin-layer chromatography, nuclear magnetic resonance, and mass spectroscopy. Over the four years we have been teaching this experiment, the students have succeeded in synthesizing the three analogues and understanding the underlying principles of SMPS and SPPS, achieving 50–70% yields of the products that were fully characterized by the aforementioned methods. The students were further assessed by an oral colloquium, their skill in the laboratory, and by a submitted report and showed a good understanding of the methodologies.
Supplement
The supplement contains information on chemicals and equipment, reagents, experimental procedures, yields, HPLC and TLC data, NMR spectra, reaction mechanisms, and a list of abbreviations.
Experiments, laboratory exercises, lecture demonstrations, and other descriptions of the use of chemicals, apparatus, instruments, computers, and computer interfaces are presented in the Journal of Chemical Education as illustrative of new or improved ideas or concepts in chemistry instruction and are directed at qualified teachers. Although every effort is made to assure and encourage safe practices and safe use of chemicals, the Journal of Chemical Education cannot assume responsibility for uses made of its published materials. Many chemicals are hazardous. Precautions for the safe use of hazardous chemicals and directions for their proper disposal are described in the Material Safety Data Sheets and on the labels. We strongly urge all those planning to use materials from our pages to make choices and to develop procedures for laboratory and classroom safety in accordance with local needs and situations.
Our Secondary School editors work hard to distill all the JCE materials to produce a fraction of particular interest to high school teachers. We call it CLIC.
In recent years we have worked hard to better match our advertisers with our readers. When shopping for chemistry education materials, visit our advertisers' WWW sites first.
Take JCE along on your outreach missions. Copies of the Journal, guest access to JCE Online, our publications catalog, and more are available for your participants.