In Part I, there was an example of a crossed Aldol Condensation leading to a mixture of products where only one may have been desired. The question was raised, how might one implement control over this reaction? It’s important to note the conditions for the reaction between acetaldehyde (Acet) and propionaldehyde (Prop) utilized NaOEt and EtOH as reagents. This particular choice of reagents leads to “thermodynamic control” over the reaction. The greatest synthetic utility of the Aldol Condensation is realized through carefully implemented kinetic control of the reaction conditions at low temperature using lithium diisopropylamide (LDA) or a comparable base for deprotonation.
In 1985-86, the primary consumers of chemists across the board were agrochemical, polymer, biopharmaceutical, and petroleum companies. Many people who were in research positions for 5, 10 and even 15 years had a B.S. or an M.S. in organic chemistry. Back then, the Ph.D. was a less common degree when compared to the number of other degrees in departments. People believed Ph.D.s were “armchair” chemists whose job was to conceive novel ideas and experiments, as well as new courses of action. The notion of how Ph.D.s apply their advanced degrees to their careers in chemistry has since then changed considerably. As the dynamics of careers in chemistry change, so must the expectations.
Some of my students tell me that the laboratory is the best part of their Organic Chemistry experience. The “laboratory experience” is meant to reinforce the lecture portion of the course, and even to provide you with a chance to have fun making things with your hands. Mentioned here are some pointers to help you get the best from the lab section of the course.
First, take the lab portion concomitantly with the lecture. Whenever possible, take the lab portion concurrently with the lecture portion of the course. When taken together, your experience in the lab will shed light and provide more intimate detail about certain topics. It will also prepare you for “laboratory based” questions on exams (they do sometimes appear). Continue reading
This article details lessons I’ve learned from students in general and Organic Chemistry. After ten years of teaching and tutoring, I’ve found common themes in questions asked by students who need my help.
“Why is this so hard?”
“Why do I have to take this – I’m not getting anything from it?”
“I can’t understand anything my teacher says.”
“This is the most difficult class I have.”
“I hate this class.”
Many times I’ve heard this from some of my brightest students, so what’s happening? Continue reading