A common complaint I have gotten from students for years centers on the “Predict the Products” section of my exams. While they can derive every mechanism for every part of every question (late in second semester, each of my 5-6 Predict the Product questions might have 3-4 reactions in sequence), they don’t have time to do so. My students want to know how they are supposed to organize all these reactions in order to move through the Predict the Product section faster.
I’ve tried “webs” or “mind maps,” and those are nice, but I keep coming back to what I call the “reaction notebook.” It is not an assignment. It’s not something I collect or grade. Students can choose to make one or not.
I advise my students to get a two-subject notebook. The first subject is the “Preparations of…” section, and the second subject is the “Reactions of…” section. Each page in each section is for a different functional group, and contains a bullet-pointed list of appropriate reactions which either make or react with each functional group. Each reaction is necessarily listed twice; once in the Preparations section and once in the Reactions section. For instance, the reaction of an alcohol with PBr3 would be listed on the preparations of an alkyl halide page and the reactions of an alcohol page.
I encourage them to write the net reaction instead of the entire mechanism. I encourage them to list any chemo-, regio-, or stereochemical points for each reaction. The PBr3 reaction should remind them it is an SN2-type mechanism, it works for primary and secondary alcohols only, and it will invert the stereocenter.
The goal is to create an index—not a complete rewriting of their entire lecture notes. If done strategically, when the student gets stuck on a Predict the Product homework question, they can turn to the specific reactions page and quickly see what that reagent does. If they can’t remember what step one does, but they know step two creates an alkene, they can work backward from the preparations of alkenes page.
While students may need to refer to the notebook frequently at first, over time they will find themselves referring less and less often while simultaneously improving their speed at the Predict the Products problems. This also works for synthesis problems. They can work backward from the intended target by referring to the appropriate preparations pages.
While students can do this with any text, Karty’s is logically set up to aid students with their reaction notebooks. His text makes it easier to complete the notebook than the previous text I used. The reaction tables at the end of each chapter list each reaction introduced in the preceding chapter. Each functional group is labelled to direct the student to the appropriate page in their reaction notebook. Each reaction also refers them back to the appropriate section in the text for more information, if needed.
There are two reasons why I particularly like the way Karty sets up the reaction tables. Firstly, there are separate columns with each reaction for the Key Electron-Rich Species and the Key Electron-Poor Species. As such, while students are filling out their notebook, they are also reinforcing the mechanistic approach. The reaction isn’t some standalone entry in an index; it directs the student to keep thinking about nucleophiles and electrophiles even outside the context of mechanisms.
Secondly, I always stress to my students, somewhat tongue-in-cheek, that the most important thing we can do as organic chemists is make carbon-carbon bonds. Any carbon-carbon bond forming reaction is automatically “more important” than any other functional group interconversion reaction. The reaction tables at the end of each chapter are split into separate tables, with one table specifically dedicated to carbon-carbon bond forming reactions. I have students dedicate an entire page of their notebooks just to carbon-carbon bond forming reactions, and again Karty’s text makes these reactions easy to find and incorporate into their notebooks.
With the old text, students had to mine their handwritten (and perhaps inaccurate) lecture notes to complete their notebooks. Now, it’s faster and easier to complete, and students can benefit from Karty’s well-thought-out organization.
I am pleased to say that probably about half of my students choose to create reaction notebooks each semester. Even though I have no quantitative data, those who create a notebook seem to perform better than those who do not. Occasionally students who have switched instructors for the second semester tell me they found the reaction notebook so helpful that they are continuing to use it!
-Adam Azman, Butler University
