Chemical Education Today
Book & Media Reviews August signals back-to-school in some parts of the country. Even if your teaching responsibilities begin after Labor Day, you can use the quieter weeks of August to ponder and perfect any changes you plan to make to your courses. The two books featured in this month’s reviews will get you started thinking about potential modifications. Need some guidance about converting your course to an online format? Check out Conquering the Content: A Step-by-Step Guide to Online Course Design by Robin M. Smith. Or does your dusty organic chemistry course need something new ? Peter Wepplo’s A Guide to Organic Chemistry Mechanisms: A Guided Inquiry Workbook just may be the solution. A Guide to Organic Chemistry Mechanisms: A Guided Inquiry Workbook by Peter Wepplo Curved Arrow Press (http://www.curvedarrowpress.com): Princeton, NJ, 2008. 404 pp. ISBN: 978-0977931309 (version with pre-bonds) or 978-0-9779313-1-6 (version with conventional curved arrows) (paper). $34.95 reviewed by Steven A. Hardinger
Reaction mechanisms are a fundamental tool of organic chemistry. Without an understanding of their accompanying curved arrows, mechanisms are just a collection of symbols for memorization. There has always been (and probably will always be) an equilibrium between an instructor’s desire for mechanistic understanding and the students’ desire for good grades via memorization (especially among aspiring health science majors). A Guide to Organic Chemistry Mechanisms: A Guided Inquiry Workbook from the aptly named Curved Arrow Press helps shift this equilibrium away from memorization by guiding students’ exploration and mastery of fundamental mechanism patterns. I requested a review copy of this book because I was intrigued by this premise, and I am excited by its potential because there are few other books that focus on introductory level curved arrow use, and none that feature the Guide’s iterative style. The author summarizes his underlying philosophy in a quote attributed to Confucius: “I hear and I forget, I see and I remember, I do and I understand.” In this case the doing is achieved through 241 mechanism problems divided among 16 chapters, whose topics include the entire range of introductory organic reactions: acid–base and ionic substitution through carbonyl chemistry, transition metal catalysis, and electro cyclic reactions. Each problem is presented in four parts, with a decreasing amount of information. In Part A, the reactants, intermediates, and products are given and the student is asked to supply the curved arrows. In Part B, the student needs to supply intermediates, as well as the arrows. Part C requires arrows, intermediates, and products. The complete mechanism is provided in Part D. The detail level decreases through successive iterations,
assisting the student in learning the mechanism details. Repetition of related mechanisms within a unit (such as ionic substitution reactions or elimination reactions) should help students see patterns within mechanism families. There is a broad coverage of reactions found in a typical one-year organic course (the only reaction I did not see is electrophilic aromatic sulfonation), as well as mechanisms not frequently addressed (such as Heck coupling or the Dakin reaction). The number of problems for any particular topic is such that an instructor will have plenty of examples for every quarter or semester of a typical one-year introductory organic chemistry course. The Guide comes in two versions, one with “pre-bonds” (dotted lines showing new bonds formed during the mechanism step) and one with conventional curved arrows. Some instructors may find the pre-bonds to be little more than clutter, but I believe they may be helpful to students struggling with the fundamental meaning of curved arrows. A Notes section provides useful comments on many mechanisms. Curved arrows are the book’s focus, so many of these notes are rather terse. Before problems begin, the Guide presents three different indexes: a general index as well as functional group preparation and functional group reaction indexes. In some aspects the topic organization does not parallel a typical introductory organic lecture course. For example, electrocyclic reactions are covered before carbonyl reactions. However, the chapters are not strongly interdependent and the topic sequence is highly flexible, so an instructor need not be tied to the given topic sequence. For the initial edition of a publication chock-full of chemical structures, it is free of significant errors, although there are a few small issues. For example, problem 80-A describes the use of AlCl3 but the mechanism is drawn with FeBr3. There are a few odd style issues such as III° carbocation instead of 3° carbocation and the inclusion of just one lone pair when an atom has two or three. None of these issues, however, is a significant drawback. Organic chemistry can be quite intimidating, but the author counteracts this with an inviting first-person voice, making the Guide feel less like a lecture and more like a one-on-one tutorial. In the second edition of this publication I would like to see mechanisms of biochemical reactions, as well a section of problems without any of the clues, to serve as a bridge between the Guide and an exam. In summary, the Guide is an innovative, engaging, guided inquiry workbook for learning mechanisms of reactions encountered in a typical one-year introductory level organic chemistry
© Division of Chemical Education • www.JCE.DivCHED.org • Vol. 86 No. 8 August 2009 • Journal of Chemical Education
927
Chemical Education Today edited by
Cheryl Baldwin Frech University of Central Oklahoma Edmond, OK 73034
lecture course. It is not a first-exposure textbook, although a full textbook from this author might be interesting. Its mission is to assist student learning of reaction mechanisms and mechanism patterns, a goal achieved with a clean and focused presentation of nearly every mechanism likely to be encountered in a traditional introductory organic chemistry course. The Guide should be recommended to every undergraduate organic chemistry student (chemistry majors and pre-meds alike), and should be within arms-reach of every organic chemistry instructor.
928
Supporting JCE Online Material
http://www.jce.divched.org/Journal/Issues/2009/Aug/abs927.html Keywords Full text (HTML and PDF) with links to cited URL
Steven A. Hardinger is a member of the Department of Chemistry & Biochemistry, UCLA, 607 Charles Young Drive East, Los Angeles, CA 90095-1569;
[email protected].
Journal of Chemical Education • Vol. 86 No. 8 August 2009 • www.JCE.DivCHED.org • © Division of Chemical Education
