Pericyclic Reactions

[LikeDaniel]

I am about to finish up Orgo 2. For our last test (excluding the cumulative final) we're covering pericyclic reactions.

So far I have an A in this class, but this content keeps tripping me up. Other than some really helpful Janci DeSpain videos on YouTube, I haven't really found much that goes more than an inch deep, but not into PhD depths...

Does anyone know of an online resource I can take advantage of?

Thanks,
-LD

Sent from my SAMSUNG-SGH-I337 using SDN mobile

---

Members don't see this ad.

 

[LikeDaniel]

In case anyone later has the same question, I did find some helpful videos, though not many.

Instead of searching for pericyclic reactions, I searched for the specific reactions and found a couple relevant ones here and there.

For Claisen Rearrangement, I highly recommend Janci DeSpain's videos. I so wish she had more videos than she does as her teaching style was perfect for me!

For Diels-Alder Cycloaddition, search for Leah4Sci and "Diels Alder Reaction Mechanism and Product Trick". She implies there are more than two videos in this "series", but I could only find the first two. Regardless, they were very helpful.

Additionally, TheOrganicChemistryTutor's "Diels Alder Reaction Mechanism, Stereochemistry, Endo vs Exo..." helped drive the point home with a lot of examples and explanations.

I was unable to find anything on the Cope Rearrangement, electrocyclic reactions, or MO/HOMO/LUMO stuff... but what I mentioned about (with some additional help talking to the professor for about 2 hours after class) helped me out and I'm fairly confident I pulled off an A on the exam.

I hope this helps someone!

 

[BerkReviewTeach]

Wow! That is so utterly nice of you to post so much helpful information for the sole purpose of helping someone you will likely never meet. Posts like yours reaffirm everything that is great about this site. Thanks for taking the time to do this.

I hope this helps a little, but the following chart can prove useful:

(space)4e-(sp6e-
light(spDisspCon
heat(spConspDis

If you recall "blue light discount" like at Kmart, then you recall that the first line in the table is "light Dis Con", telling us that 4e- systems will undergo disrotatory pericyclic reactions when driven by light and undergo conrotatory pericyclic reactions when driven by heat. With 6e- systems, it is just the opposite. So if you have a molecule like trans,cis,trans 2,4,6-octatriene (a 6e- system), where if you draw it lined up to undergo a pericyclic ring closing, carbons 1 and 8 are pointing out and away from one another, then using heat will result in a disrotatory process that rotates the two methyl groups (Cs 1 and 8) into a cis orientation in the new ring.

I'm not sure if this is helpful without a picture, but the point is that if you know that table and can draw the structures correctly, it all falls into place nicely.

 

[NextStepTutor_1]

Hi @LikeDaniel -

Congratulations on your great work in O-Chem 2! Sounds like you're doing very well in the class, and the fact that you're really trying to understand the material bodes very well for you in that class and eventually for the MCAT.

Since this is on an MCAT forum, though, just a quick word of caution regarding o-chem on the MCAT: when the time comes for you to study for the MCAT, you'll want to be sure to target your MCAT studying to focus on the o-chem topics that are specifically on the MCAT. O-chem is an important part of the current MCAT, accounting for ~15% of the Chemical and Physical Foundations section and ~5% of the Biological and Biochemical Foundations section, but the way that o-chem is tested on the MCAT does not correspond super-closely with the content of most orgo 2 courses in particular.

The gold standard for what is on the MCAT is the AAMC content outline (search for "AAMC what's on the MCAT" and you'll be able to find the full PDF). All o-chem topics are noted with "OC" in parentheses. By far, the heaviest focus is on: (1) stereochemistry, (2) basic functional groups/reactions, (3) lab techniques, and (4) crossover with biochem. Third-party test prep materials will reflect this focus.

Best of luck in your studies & on the MCAT!

 

[LikeDaniel]

Hi thank you for the word of warning. 🙂

Originally I posted this in the Nontraditional Students forum because I both wanted to know advice to help protect my GPA and wanted the opportunity to discuss my class with peers. Apparently a moderator moved it here into the MCAT forum.

I currently have an outdated list of what's on the MCAT and was surprised to see it moved as I didn't remember percyclics being tested on the MCAT (or at least tested much).

Anyway, thank you very much for the heads up. I fully agree that studying everything in all those classes is not only a misuse of time, but also unlikely to be achievable. 🙂

Sent from my SAMSUNG-SGH-I337 using SDN mobile

 

[NextStepTutor_1]

Hi @LikeDaniel -

Ah, gotcha! Well, in any case, congrats again on your great progress & best of luck!