Can you help me wrap my head around organic chemistry synthesis?

September 12, 2016 12:02 AM

I took the first half of organic chemistry and really struggled through synthesis. I have to take the second half this spring and I am really scared. Do you have any tricks/magical methods to help me beat it into my head?

I took organic Chemistry I this last spring and I got an A. Barely. We used the book and learning method set forth by David Klein where you spend the first half of the semester learning some fundamental skills and concepts and then launching into synthesis the second half. We did substitution reactions, alkenes, alkynes, and just started to touch on alcohols.

The first half of the semester, I totally smoked it. Had a solid A and was loving it. Second half of the semester was a crash and burn. I just couldn't get synthesis to stick in any way. I literally spent the last day before the end of the semester having uncontrollable fits of stress-crying while trying to pull myself together and pass the fucking final. I think I got in the 88 percentile on the national exam which isn't bad but I felt like a total failure because it was obvious I pretty much failed the real meat of ochem and I am not used to failing at this sort of thing.

Due to space issues in organic chem II, I haven't taken the class yet and will be taking it in the spring. I am deathly afraid of it, especially since it will have been a whole year since the first half. I have got to get my head around synthesis. It feels like I am not studying it correctly, like, if I just find that magical way, it will click and I will be fine.

If you got through ochemII, please tell me how you did it. I don't want a whole semester of stress crying and hair falling out, I just want to pass this class. Please hope me.

posted by Foam Pants to Education (9 answers total)

I feel you. I studied Chem.Eng. and had to take the entire gamut of OChem, IChem, PhysChem, etc.etc. OChem was a killer for me despite high school AP Chem. I combined 2 different ways, number 1: read, read, read and just pound reactions into your head. I wrote them out, I drew them out, I pushed electrons all around to visualise what the textbook was attempting to explain to me. Number 2: trying to understand the fact that synthesis is the culmination of what has the *greatest potential to occur under any given situation*. So, there I was as well, mapping out what were the potential pathways this reaction could take, and why the one in the textbook was the path that had the highest potential to occur under the specified conditions. I cannot say I feel I mastered OChem, but, since a lot of my career has been paint and polymer research, I have a good grasp of it :) To this day a buddy who went on to do his PhD in organic synthesis talks to me about his job on an incomprehensible level for me..... but, he's dedicated to synthesis as a career and passion.

good luck!
posted by alchemist at 3:48 AM on September 12, 2016

I had a not entirely dissimilar experience in orgo. I think the thing that really threw me was that I really do better at memorizing underlying principles then figuring out from there - ie little memorization, much rationalization. It's a pretty good approach for a lot of chemistry. But my experience was that studying for orgo really needs moving away from that - there ARE underlying principles, but the level of complexity is such that you aren't likely to get so far working that way, and you'd really do better just committing to memorizing a LOT of reactions.

I was barely passing most of the second semester, Cs and Ds, and seriously thinking about changing my major even, until I finally just accepted I needed to change my approach, and after (as the aptly named alchemist put it) pounding reactions in my head, so convincingly nailed the final that the professor made my average the lower bound of an A for that semester.
posted by solotoro at 3:53 AM on September 12, 2016

I have taught college-level chemistry in the past, including a little organic.

I know thread sitting is discouraged, but it might help to have an idea of why you're taking the O chem series. Are you a chem major? Chemical engineering? Premed?

I ask because you are clearly super-anxious about this, and I think that anxiety is going to work against you, no matter what. So, why are you taking organic, and where does it fit into the larger scheme? Are you going to be expected to use it extensively in your further studies, or do you need passing familiarity to give context about other subjects where you will specialize more? Because--Getting an 88 on the national exam is great, and getting an A in the first class of the series is also great. You hit a wall where things that had started out coming easy to you, then did not come so easy to you, which is normal and to be expected in university-level study. Beating yourself up about it is not helpful. So, I encourage you to show yourself some compassion, first, and also put it into some perspective. If you don't know how to really put it in perspective, go talk to your adviser to help you with this.

I haven't used that specific method/text, but the approach of really focusing on fundamental skills/concepts and then relating them to mechanisms and reaction processes is a good one. Organic is usually really challenging to science students who are accustomed to being mathematical and logical, because it's more about interrelatedness and layers and probabilities. Some people just grok it right away and many others (me included) really have to bang on it for a long time before it starts to make sense.

Probably the only concept that helped me make it a lot easier to get is thinking of electrons/electron density as being kind of like water. Water moves and flows and follows certain principles, like it moves downhill and around solid objects. Electrons move and flow, too, but following their own principles, like toward positive charge and away from negative charge, and in specific patterns related to orbital shape. Electrons aren't moving like the dots on paper, they're pouring from one orbital configuration to another. Dot-pushing representations don't help with this, so maybe see if you can find some visualizations online that depict it more graphically, and that may help.

Since you've got a big break between the first term and the second term, it's not going to help if those fundamental concepts kind of drift off before you get back into it in the spring. So, put some effort into keeping it fresh in your mind this fall term. A great way to do that, that builds in some accountability and help, would be to get a tutor. Maybe meet once a week. I would suggest working your way through the material from the second half of your first class with your tutor, and focus on making sure you understand how those fundamental concepts/skills relate to the reactions you're learning.

Good luck!
posted by Sublimity at 4:20 AM on September 12, 2016 [2 favorites]

The first time I took Organic I, I got a C-, because I didn't get synthesis at all. The next go around, I got an A in both I and II.

Admittedly I probably didn't study hard enough the first time taking Organic I, but I also didn't study effectively enough, which I think made all the difference when I retook I and moved on to II.

Here is what worked for me:

I spent a lot of time over winter break memorizing reagents. I made flashcards by hand and then scanned them into spaced repetition software during Organic I, then just continued plugging away at them over the break so I wouldn't forget them.

I specifically made them so the reagent was on one side and a reaction diagram was on the other, then studied them both directions (name the reagent/reaction conditions sometimes, vs describe the reaction that reagent performs sometimes). I put the electron pushing arrows on the flashcards almost every time. You are in luck because you have a lot of time before the spring to get your memorization game on lockdown.

To study synthesis specifically, I did every synthesis problem in my book by the end of the course. Literally, every single one. Sometimes I would do the problem in the fewest steps I could think of, then repeat it doing the same synthesis with a less efficient number of intermediates just to know I could get from point A to point B in different ways in case I had to punt on an exam problem. If I got stuck on a problem, I noted it down and took it to office hours with all the ways I had tried already. Then I specifically studied whichever reaction I couldn't fit into the scheme after the instructor showed me whatever I did wrong. Both how to use it and why it works.

The best way I found to conceptualize synthesis was not working backwards, like a lot of people tried to tell me to work. I kind of worked from the middle of the problem out. I got a big picture idea of what kinds of steps I thought I would need to perform, and then came up with an intermediate which would offer me the right amount of flexibility. Then I pushed electrons around worked from that intermediate in both directions as needed. Then I looked at the synthesis as a whole and tried to make it more efficient. For longer syntheses, I came up with two or more flexible intermediates and did basically the same process.

This method took a lot of scratch paper and was time consuming at first, but by exam time it was like second nature because I had done it enough that it clicked in my head and the paths were much clearer.

As for the chemistry related anxiety, a lot of times I studied the flashcards on the bike at the gym. I don't know why it worked so much magic on my brain, but it did.
posted by skyl1n3 at 4:45 AM on September 12, 2016 [1 favorite]

Firstly: you're going to be fine!! Take a deep breath. Let it out. You're going to be fine.

Secondly: synthesis is all about pattern recognition. This can be a hard thing to flow with for an analytical person (which it sounds like you might be, and I certainly am) because it is largely about learning things without realizing that you are learning them. Although you will learn many things consciously -- "if I see this type of compound, reagents X, Y, and Z may be useful for synthesizing it" -- many of the skills you need for synthesis problems will be firmly ingrained in your subconscious -- "why did I use a Grignard? It just seemed like the best way to get there. I had a feeling. Maybe it reminded me of something I've seen before."

I do most of my learning with the former method so it took me some time to get accustomed to synthesis and I certainly considered it a challenge. My advice is unfortunately nothing groundbreaking: you need to do practice problems; you need to do a lot of them. You need to write them down by hand on a piece of paper without looking at the answer key; once you have tried your hardest, you need to look at the answer key and use it to markup your solutions. Now is a fantastic time to start (if you don't already) using several different colors of pen. Don't erase the mistakes you've made -- mark them in a fabulous color that stands out. Look back over your mistakes. Save them. Review them the next day and think about the places where you got stuck, the reagents you could have used, the places where you used three steps but could have used two.

If you practice synthesis problems every day (and really practice them -- feeling helpless and copying answers out of the solutions manual is not going to help you), you will become good at synthesis. Your subconscious will see things in the problems that your analytical mind does not. It is a process that is by turns immensely satisfying and soul crushingly frustrating. I know.

Once you've done all the practice problems in Klein, consider using Bruice as well (your library probably has a copy on reserve). I used Bruice primarily but turned to Klein a few times when I ran out of problems before I felt really good about a topic.

Good luck!
posted by telegraph at 6:08 AM on September 12, 2016

Nthing "Do you really need to do more organic chemistry?" and memorisation and practise and lots of it. Make sure you revise during this semester so you don't forget what you do already know. Could you sit in on the last few lectures of Org I this semester? It might make more sense second go round when you don't have an exam to do.

I was super great at chemistry until I hit the more advanced organic chem, at which point it all merged into a blur of hexagons, dots, arrows and white powders (the lab work was sooooo boring. make one white powder into another white powder. yay.) I think there's something in the idea that chemistry makes sense and appeals to a certain type of brain, but org chem is different, and so needs to be attacked differently.

I think what I did was really drill down and solidify the reactions that were easier to remember, e.g. esters, carboxylic acids, breaking double bonds. And then did my best with repetition and flash cards for the rest. Knowing I knew enough of the easier stuff to pass reduced my anxiety enough to take educated guesses for the rest. I passed, and now I'm super good at drawing hexagons.
posted by kjs4 at 6:22 AM on September 12, 2016

You've got a few months that you can spend getting into a routine of unstructured learning -- no class schedules, no specific learning/teaching format, no tests. Take the opportunity to keep yourself exposed to and engaged with the material you've just learned (and the material you'll be learning). Youtube wasn't around when I was struggling through organic chemistry in the late 90s, but my word it's such a helpful resource. Ditto Khan Academy, iTunes university, and so on. Watch one video lecture every three days, maybe don't even worry bout taking notes. Just listen and focus.

I say this because a tremendous amount of the difficulty learning organic chemistry is that there's a tremendous amount of conceptual material you've got to pick up. It's like a new language, with its own conventions and syntax and grammar. And like picking up a new language sometimes you have to stop trying to be so intentionally directed and just, you know, watch a dang movie in French with the subtitles on. Fluency doesn't come from the classroom alone.

And really, take a deep breath. It's not life or death. It'll be difficult and you might not get an A. Your grade isn't the purpose, it's just a measure. The longer you spend learning the material, if you need it, the easier it'll get. I promise.

Sincerely, toxicologist who hated hated hated my first o. chem. class with a passion.
posted by late afternoon dreaming hotel at 9:01 AM on September 12, 2016

I don't know how helpful this will be to you, but I can say from experience that learning the synthesis is a lot of work, BUT you need to relax about it. Put in the time to learn the problems. Go to class regularly, do the homework, ask questions, go to office hours. But relax. Failure to get it the first time is not dooming you to failure as a person.

Signed, a successful, gainfully-employed PhD who bombed the fuck out of OChem II the first time he took it.

(As I always told students after that experience: Failing one course won't kill your career, but be damned sure you 4.0 the thing when you re-take it. Failure is an experience that I think more of us should experience. You learn more from failing and subsequently recovering from that failure than you ever do from continual, unblemished success.)
posted by caution live frogs at 12:08 PM on September 12, 2016

Two things that helped me in organic chemistry:
1. Reminding myself that learning organic chemistry was a lot like practicing an instrument: it has to be done every day for the pattern recognition to really stick, and
2. Organic Chemistry As A Second Language - this is a very small workbook that helped hammer the first point home.
posted by gemutlichkeit at 5:31 PM on September 12, 2016