How I Aced Organic
(This is an excerpt from several messages between a student and myself. I have removed the headers.)
Date: October 21, 2007 1:27:09 PM EDT
Subject: TLOC - Purchase Inquiry (10/21/07)
21 October 2007
Could you sell a hard-copy of TLOC, ...
Certainly, just send a $35 money order to …
and I'll answer any questions you might have. What text are you using?
Ege, 6th ed. (http://college.hmco.com/chemistry/organic/ege/organic_chem/5e/instructors/)
Actually, the class had the option of using the book we used for orgChem I or getting the newly adopted bruice, 5th ed.
I am having some difficulty with reaction mechanisms or, more specifically, combining multiple mechanisms to reach final products. I'd like to think that the professor is simply using more examples and/or test bank material from the bruice book, as I am not faring as well as I would like on his quizzes. I would just like more exposure to the basic concepts involved in the mechanisms we are studying this semester.
I had used an early version of Ege, but we too switched to Bruice. TLOC was roughly formed around Bruice...
If you are using Bruice in your class, I can tell you which problems from TLOC will match the chapters. I don't know that I can do that with Ege.
while I plan to master all mechanisms necessary to understand the orgChem reactions we are studying, what I currently need help with are chapters 16-18 in bruice, 5th ed.
I have a quiz in orgChem II on wednesday.
Are you able to learn the reactions or do you have questions? As you work on it. Make absolutely certain that your curved arrows are 100% correct. There cannot be any errors at that stage as it contains the logic of a reaction. The problems are written correctly. You just need to follow it.
I don't know how much you know, but past experience tells me you are or may be learning the reactions for the first time. You probably pattern matched to products before, and now the problems are getting a lot more difficult and that doesn't work. This seems simple to me, but if a chapter is on additions to a carbonyl group, that is the very first step in all of the reactions. I am always surprised when I see some other reaction being written. That is one of the things I liked about Bruice. For each chapter, you should have some idea about the reactions.
The more you do, the easier it gets!
I am learning these reactions for the first time. you're correct, in that I have previously worked on (looked for) patterns.
**quick question: would a list of reagents going and list corresponding "attacks"/"mini-reactions" be a futile exercise? or would this lend itself to your methods?
I really don't know the answer to that question. Early in my teaching career, I had planned to prepare lists like that. Paula Bruice has such a list in her book, but I can't say whether it is a valued exercise.
If you were to ask which effort would bring a greater likelihood of success, knowing whether a given reagent will attack or to memorize reactants and products versus knowing how a reaction takes place, I'd argue knowing how a reaction takes place is more valuable. If you were to substitute another reagent in place of the one you memorized, I don't know if you would know what the product would be because the problem has changed. If you know how the reaction takes place, then you will have some mechanistic expectation of the new reagent. If it must add to a carbonyl group, does it have electrons that can be donated? If the electrons are between a carbon and a metal, you can use a generalization that the metal never holds the electrons. If you noted my Chapter 1 discussion about atoms, you would know that carbon does not hold its electrons very closely. Therefore they are available for reaction.
In class, I began to expect that students who used flash cards would score lower than those that just learned mechanisms. Flash cards may be fast and easy, but they didn't follow my thinking of how our brains learn the language of organic chemistry. Mechanisms contain a chemical logic ...
What I don't know about your class is whether your instructor waters down mechanisms and reactions. Does he avoid either? Does he focus on nomenclature or ??? (fill in topic)? Some instructors choose a book to avoid mechanisms.
my prof has been laying out all the mechanisms, but very quickly. he doesn't really go into the steps involved. he just shows the mechanism, says "this is such and such mechanism", then moves to the next. there are plenty in the carbonyl-specific section.
Sometimes I used slides from Part A, and added the curved arrows. I did that just so I could discuss the reactions. Since students had the reactions also, they could fill them in. That probably wasn't as good as just walking around the class and asking the students to fill them in. If students made common errors, then I would make announcements or think about how I needed to change my book.
I am amazed at how much I can do already with the help of your work. just yesterday morning, I couldn't predict products or suggest reactants for reactions involving acyl halides, anhydrides and esters. now, it seems sort of silly that I had such a hard time with these at all. during breaks at work and over lunch, I have just been writing them out .... doing practice problems ... reviewing mistakes, which are not as frequent now ... writing them out again ... practice problems, etc.
I am moving into amides and nitriles tonight. tomorrow, on to acid/base catalyzed hydrolysis ... this is becoming fun ... almost like a puzzle. I can tell where things must "fit" once I know what they are reacting with or what they will become. I can see where trying to memorize reactants wouldn't really serve my understanding too well. I may forget a step/reactant working this way.
Thank you for the endorsement. Although I didn't always hear such comments, but I heard them pretty frequently. I would not have ventured into trying to market this book unless I had students telling me this.
If you like the book, tell your friends and tell your professor.
I just wanted to let you know ... I had an exam in OrgChemII on Monday of this week. I got an 89% (class avg was about 49%). I am sure the improved performance I enjoyed was due primarily to your text AND heeding your encouragement to actually write the mechanisms out instead of trying to memorize the reactants, products, etc. I had heard that this was necessary before. This argument, coming from you, was apparently what I needed to get in gear.
I am pleased to learn of your good results. Students able to get 89% are the kind of students I want to attract. So you went into the exam with knowing how reactions take place and voila, you could predict the product with that knowledge. This seems too simple, doesn't it?
Tell your friends.
I hope this message finds you well. I wanted to thank you again for TLOC. I believe the practice I had in using your book really helped with my overall understanding of organic chemistry mechanisms.
My organic chemistry II final was last week. I got an A in the class.
I am pleased to learn of your results, and I am happy that you persevered. It seems obvious to me that you should be able to solve at least one example of a problem to solve another similar problem, but it is difficult to get students to follow that advice, especially in my absence. What you did is what I did in college and your results are my results. For this reason, I love getting good students to use my book, they usually do really well. You simply validate what I saw in my classes. I have less knowledge of how students do in other classes, so I am pleased to learn of your results.
PS, thanks for giving me all of the great quotes, see www.curvedarrowpress.com for your others. This too will make it there (eventually).