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Projects That Assist with Content in a Traditional Organic Chemistry Course John J. Esteb, John R. Magers, LuAnne McNulty, and Anne M. Wilson* Department of Chemistry, Butler University, Indianapolis, IN 46208; *
[email protected] Science instructors have long struggled to engage students in the classroom. From the recognition that science is a foreign language (1), to current movements to adopt a discovery-based learning (a.k.a., inquiry-based learning, guided inquiry, collaborative learning, active learning, hands-on learning, etc.) pedagogy (2), to laboratories that engage students in practical applications of chemistry (3), combinations of laboratory with lecture (4), additional methods by which professors can create a more intellectually stimulating classroom are still sought. However, at a certain stage in course development, content has to become the focus of the educational process at the college level, especially in upper-level courses. There are some courses that are, at their heart, content-based. What specific activities can be done in contentdriven courses, such as organic chemistry, to engage their students when the content is the driving force for the course? Pedagogical models for teaching this course have been presented (2e, g ). However, we were searching for more concrete and long-term activities to engage our students over both semesters of our year-long course sequence. Our organic chemistry class sizes typically range from 50 to 75 with laboratory sections of a maximum of 24 students. We teach a diverse group of students who have differing reasons for taking our organic chemistry course. We have pre-pharmacy students, pre-physician assistant students, preprofessional students (pre-medicine, pre-veterinary, pre-optometry, etc.) from a variety of majors and science students who intend to go to graduate school or obtain a job directly after graduation. Given these divergent needs, we have to balance our content choices, carefully weighing depth with breadth, while covering those topics that are the accepted canon of organic chemistry. This list contains neither optional material, nor topics that we have to allow the students to discover for themselves. It represents over 100 years of scientific research, and our students’ understanding of the subject matter will be assessed by extramural sources (GRE, MCAT, PCAT, etc.). The common thread for all of our students is a need for the content and the ability to utilize and apply the problem-solving skills developed in this foundation course. The two projects we describe are adaptable to the changing needs of the individual class. These projects are: (i) the reaction notebook and (ii) the end-of-semester synthesis activity. Each of these projects leads to intellectual ownership of the material and a sense of discovery while still maintaining rigorous content standards. In addition, each student has created a long-term study aid (the reaction notebook) and has completed a cumulative project (the synthesis activity). The Reaction Notebook Each semester, we encourage students to put together their own reference book filled with reactions covered in the course. This notebook is compiled on the students’ time. This www.JCE.DivCHED.org
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is not required nor is it graded, but the majority of students who take the course (and over 75% of the students who earn A’s and B’s) complete at least a portion of the notebook. This reaction notebook consists of three parts: (i) the forward reactions, for example, reactions of alcohols; (ii) a common product section, for example, how to make alkenes; and (iii) classification of reactions into categories with similar mechanisms, for example, radical-based reactions. Having each student make and use personal reference material encourages understanding and not memorization. We have found that having the students engage in the process of pulling the details of the reactions together, focusing on the important parts, and creating their own study tool was extremely valuable to the individuals. This moved them beyond a jumbled “flashcards of reactions” study habit into an “organized understanding” of the reactions covered in lecture. The students are then more able to see trends and begin to predict products in more complicated, never-before-seen reactions. The first section of the notebook is easily compiled from the students’ lecture notes and textbook. The majority of textbooks arrange the subject of organic chemistry into chapters that reflect reactions of a particular functional group. This universal organization scheme of the textbook, and often the lecture, gives the students confidence in starting the reaction notebook. In addition, the students have lists at the end of each textbook chapter to consult to make sure that no reaction has been inadvertently omitted. The second section of the notebook is the common product section, which is an area not covered in textbooks. This section is the first section that has students engage in independent work. They must discern which reactions give the same kinds of products and organize them appropriately. We have utilized this exercise to help the students begin to think about more complex synthesis problems and grasp that there is often more than one way to obtain the same product. This leaves room for creativity in problem solving and leads to a more sophisticated understanding of the abundance of reactions that the students are required to learn. The third and final section of the reaction notebook classifies all the reactions by mechanism type, also overlooked by many textbooks. This grouping is the most intellectually demanding project to undertake. To make the determination, the student must determine and understand how reactions work. By classifying the reactions into categories, students should be able to see trends, similarities, and relationships between substrates and their products. While working on the notebook and upon completing sections, the students garner a great sense of accomplishment. The pride that the students have in their notebooks is not to be underestimated. The students make and use them as a study guide and resource for the entire school year, in other course sequences (i.e., biochemistry, physiology, cellular biology, etc.), and as preparation for standardized exams. We
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In the Classroom
have heard that some students who move on to graduate programs in organic chemistry continue to add to their reaction notebooks.
Conclusions
The End-of-Semester Synthesis Activity In the typical advanced-level college course, a comprehensive paper or final project is often assigned in addition to exams. In a course such as organic chemistry, a comprehensive paper is not always appropriate, and it has been a struggle to find a project that would both benefit the student and adequately serve as a comprehensive assignment. An “on-paper” project involving a unique synthesis target for each student has been found to serve this purpose well. Over a period of four years, the organic faculty members have built up a library of synthesis targets that utilize a broad array of the reactions covered for the semester. Depending on the faculty member, tenor of the class, or the methodology by which synthesis has been approached, the “ground rules” for this project have varied. They may include different allowable starting materials (e.g., alcohols of five carbons or less), a requirement that the students synthesize their target using two different routes, choosing the key step of a synthetic route and supporting that choice, including a reflection on the purpose of the project, predicting spectroscopic data for their targets, and listing all collaborators on the project (all students collaborate with lecture notes and the text). A more discovery-based learning model could work in this case, but it is our feeling that students still benefit from added direction given our time restraints. Upon completion of the project but before the due date, we have also experimented with setting aside a lecture period to have students present their synthesis routes. This gives the students time to give feedback to one another and serves as an excellent “student-run review” at the end of the semester. Often, the students identify problem areas and make suggestions to their colleagues. This also gave the instructor an opportunity to see the deficiencies in the application of knowledge. If the class as a whole was unable to identify a problem area, it would be unlikely that they would recognize it on an exam. The most challenging aspect of this project has been accumulating the library of target molecules. By brainstorming with other faculty members and sharing our lists, we have managed to generate a list of over 200 synthetic targets. We can pick and choose from our lists, which allows us to provide diversity and keep things from being the “same old thing” each year. Students have provided positive feedback on this classroom assignment and have felt that it has helped them
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crystallize their thought process and their overall understanding of synthesis.
Both of these activities encourage the students to think more deeply about the subject material. In addition, each of these activities can be performed in classes of up to 70 students and neither activity utilizes significant lecture time nor sacrifices content. Both activities encourage aggregation of accumulated knowledge and are excellent sources for review of material. In fact, the reaction notebook is often helpful for the end-of-semester synthesis activity. We feel that these two activities have creatively and successfully addressed a need to engage our students with the material in the classroom setting. W
Supplemental Material
Instructions for the students including two examples of the end-of-semester activity and notes for the instructor are available in this issue of JCE Online. Literature Cited 1. (a) Long, S. J. Chem. Educ. 2004, 81, 1254–1255. (b) Markow, P. J. Chem. Educ. 1988, 65, 57–58. 2. (a) The National Science Foundation has promoted inquirybased learning in science, mathematics and engineering since 1996. http://www.nsf.gov/pubs/2004/nsf04201/FY20032008.pdf (accessed Sep 2006). (b) Graves, T. Educ. Leadership 1991, 48 (7), 77–79. (c) Wenzel, T. J. Anal. Chem. 2000, 72, 293A–296A. (d) Wenzel, T. J. Anal. Chem. 2000, 72, 359A361A. (e) Paulson, D. R. J. Chem. Educ. 1999, 76, 1136– 1140. (f ) Delaware, D. L.; Fountain, K. R. J. Chem. Educ. 1996, 73, 116–119. (g) Fountain, K. R. J. Chem. Educ. 1997, 74, 354–360. (h) Harvey, L. C.; Hodges, L. C. Chem. Educator 1999, 4, 89–93. 3. (a) Sanchez, M. J. Chem. Educ. 1987, 64, 964. (b) Mohrig, J. R. J. Chem. Educ. 2004, 81, 1083–1084. (c) Mullins, R. J.; Verdernikov, A.; Viswanathan, R. J. Chem. Educ. 2004, 81, 1357–1361. (d) Whelan, R. J.; Hannon, T. E.; Rakestraw, D. J.; Zare, R. N. J. Chem. Educ. 2004, 81, 1299–1302. (e) Hass, M. A. J. Chem. Educ. 2000, 77, 1035–1038. 4. (a) Meany, J. E.; Minderhout, V.; Pocker, Y. J. Chem. Educ. 2001, 78, 204–207. (b) Montes, I.; Lai, C.; Snabria, D. J. Chem. Educ. 2003, 80, 447–449. (c) Browne, L. M.; Blackburn, E. V. J. Chem. Educ. 1999, 76, 1104–1107. (d) Montes, I.; Prieto, J. A.; Garcia, M. Chem. Educator 2002, 7, 293–296.
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