In my recent post, Better at Mechanisms, Better at Synthesis, I highlighted research by Alison Flynn at the University of Ottawa, in which she showed that students have better success solving a synthesis problem when they draw reaction mechanisms.
I recently had an opportunity to further probe this connection by analyzing my students’ success on a handful of problems from the second of three in-class exams in my Organic 2 course. Would students who demonstrated mastery of mechanisms also score better on the exam’s synthesis problems?
My exam covered reactions from Chapter 18 (Nucleophilic Addition to Polar Bonds 2) and Chapter 20 (Nucleophilic Addition–Elimination Reactions 1), synthesis strategies from Chapter 19 (Organic Synthesis 2), and also NMR and mass spectrometry from Chapter 16 (Structure Determination 2). Nine of my 26 exam questions provided students with reactants and reaction conditions and asked for the detailed mechanism and major organic product. I also gave the following three synthesis problems:
After I finished grading my exams, I selected the following three mechanism questions to analyze, which were among the more challenging of these types of problems on the exam:
Exam by exam, I summed the points each student earned on these three mechanism problems. and I separately summed the points the student earned on the three synthesis problems. I then made note of which students scored above or below 73% (the overall exam average) on the three mechanism problems and I also made note of which students scored above or below 73% on the three synthesis problems. Comparing the two performances for each student, here’s what I found:
-93% of the students who scored above the 73% cutoff on the mechanism
problems also scored above the 73% cutoff on the synthesis problems.
-80% of the students who scored below the 73% cutoff on the mechanism
problems also scored below the 73% cutoff on the synthesis problems.
The take-home message? A student’s ability to solve synthesis problems does indeed seem to go hand-in-hand with a student’s mastery of mechanisms .
-Joel Karty, Elon University, Author.
Photo credit: Image Source/Getty Images