Diels Alder Reaction Stereochemistry and Endo vs Exo Products

[@SmokeyHooder]

The tricks for remembering or understand things that you present makes these videos invaluable for learning organic chemistry. Like the close parable. Brilliant.

[@Leah4sci]

Glad you liked it, I try anything I can to make things memorable and understandable. Thanks for watching!

[@emmanuelletoussaint287]

One of the topics for my quiz tomorrow is Diels-Alder rxns and this video was definitely very helpful! Thank you for all that you do!

[@Leah4sci]

Glad this came at a perfect time! hope you aced your quiz

[@Sijo2]

Your amazing!!! Every video watch, you make chemistry so easy to under stand. Thank you

[@Leah4sci]

Wow, you're very welcome! I appreciate the compliments. :)

[@诗舞翩翩]

than k you for your help! its even more helpful than my classes !

[@Leah4sci]

Happy to help!

[@shanemichael9404]

I am going to be tutoring a college student who is young and bright and she's sure to be a success in the near future. I find your videos refreshing as I brush up on my orgo. chem. I also told her about your entire you tube collection of videos which if she studies carefully, she won't even need tutoring. Chemistry might be one of my favorite subjects, but not for others, that's for sure. I didn't want to reach out to you on messenger, (as it has been a few years since I have) because I figured you're probably too busy and that's a little on the personal side anyway. I'm the guy who was studying just to learn more, but for no other reason. I had no deadlines to meet. I Hope this message finds you doing well. Thanks again !

[@Leah4sci]

Hi! Great to hear from you and excited to hear that you are finding a way to let your passion for chemistry help others. Thanks for passing my information along to your student, thank you!

[@pimpjuiceT]

concise and very clearly explained, thank you!

[@Leah4sci]

You're very welcome! That was my goal, I'm so glad you found it helpful!!

[@nate2376]

For the part at 2:40, I thought it does not matter if it’s in or out but more so if facing the same way or different directions they are cis or trans respectively

[@Leah4sci]

You're correct. The inside and outside groups must end up with the correct relationship to each other, regardless of whether they are facing you (the observer) or not. But also bear in mind that they must be appropriately positioned in relation to any groups that the dienophile might have.

[@saaniyahsajed1932]

you're the best. thank you so much for explaining these so well!

[@Leah4sci]

Aww you're so kind, and you're welcome!

[@jayc6894]

your memory devices are really helpful: make-break-make, the endo/enter and exo/exit, and the rest are great

[@Leah4sci]

So happy to hear that this resonated with you. There's time for overthinking on other problems but something like this should be straight-forward if it can be. Hope it helps

[@hej-ky4qk]

thank you, you helped me a lot :)

[@Leah4sci]

You are welcome!

[@meethiaasali792]

thank you leah, you are a life saver

[@Leah4sci]

You're very welcome

[@naeemoxychem]

Thanks for such a niche representation with tricks

[@Leah4sci]

you're so welcome

[@shuaichenglai7641]

very very helpful, thank you so much

[@Leah4sci]

You're very welcome!

[@9247173757]

Excellent teachings

[@Leah4sci]

Thank you!

[@GodOnVayne]

Thank you Leah! This helped me a lot.

[@Leah4sci]

You're so welcome!

[@andreifabre1581]

I believe all of this reactions are when the dienophile attacks from the bottom, but when it attach from the top does every thing is inverse?

[@Leah4sci]

Both endo and exo products can be formed, based on the stereochemistry of the specific reaction. For help with questions like this and more, I recommend joining the organic chemistry study hall. Details: leah4sci.com/join or contact me through my website leah4sci.com/contact/

[@yusefsadik8653]

The Diels Alder reaction is so satisfactory, specially when you get cyclohexenes

[@Leah4sci]

yes!

[@usernamehere94]

Great video, thank you so much for sharing!

[@Leah4sci]

You're very welcome!

[@patrycjapajdak2491]

a very useful video, thank you :))

[@Leah4sci]

Glad you liked it!

[@loganblaskie1759]

This video is fine if you just want to pass your organic chemistry test and never think about organic chemistry again, but if you are interested in actually learning about organic chemistry on a deeper level I would not recommend this video. I would recommend taking the time to look at the transition state and how the diene and dienophile approach each other in the reactant complex, then consider how it would effect the resulting stereochemistry. This video fails to address the 'why' of the stereochemistry in favor of mnemonics that you will likely forget long before the geometric and mechanistic underpinnings of this reaction.

[@Leah4sci]

As you noted, this is a short video to give a very specific answer to a very specific issue. I go into deeper dives in the Study Hall.

[@adamsilvester978]

​@@Leah4sci what's the Study Hall? 🤩

[@A-Ls1]

Okay I see it’s straight up and down

[@Leah4sci]

Good deal!

[@NewWesternFront]

So you get enantiomers when all the chiral centers on a molecule are inverted in their absolute configuration. And we can see that those two structures become diastereomeric because that methyl configuration is retained. This is how I think to explain your “challenge”. I was having a little trouble finding a simpler answer in a plane/mirror of symmetry. What do you say?

[@Leah4sci]

That's the exact explanation I would give! The addition of a chiral center whose configuration is retained in both structures (while the other centers change) gives us diastereomers.

[@japvir3694]

Very usefull for jee exam

[@Leah4sci]

Happy to help!

[@nate2376]

How do you choose endo/exo when the dienophile is trans

[@Leah4sci]

you get both

[@arjunsinha4015]

Great Video

[@Leah4sci]

Thank you!

[@amine_Raf]

Great explanation, but how about facial approaches, I always find that most Diels-Alder courses don't discuss their effect on stereochemistry despite their importance in organic synthesis involving DA reactions. How would you say the facial approach of a dienophile affects the stereochemistry and the number of theoretically possible stereoisomers?

[@Leah4sci]

I'm not sure I understand your question, do you mean the products when approached from the top and bottom respectively?

[@amine_Raf]

@@Leah4sci Yes, That's what I mean. Wouldn't the approach from the bottom result in a product with a different stereochemistry than the product of the approach from the top?

[@kewang4683]

Great video ! You should be my college professor!

[@Leah4sci]

Thanks! But if I was, I wouldn’t be able to help as many students as I do on my website and KZbin.

[@user-dl1yt7yk3r]

in the beginning, did you say that they are sp2 (the diene and dienophile) because there is resonance? I have difficulty figuring out when it is sp2 or sp3

[@user-bm4kr2hj1m]

You can determine it by checking if there is a pi bond

[@Leah4sci]

Any carbon holding a pi bond is sp2 hybridized unless it has 2 pi bonds (triple) making it sp. Most reactive carbons on the diene and dienophile will be sp2

[@ZeinabYusuf]

mmm girl you ate this up

[@Leah4sci]

Thanks, I appreciate the compliment!

[@marcusp.7512]

thank you!

[@Leah4sci]

You're welcome!

[@ΛευτέρηςΚ-ε8θ]

Isnt the last compound a meso compound? Can that exist in 2 isomers?

[@Leah4sci]

The two compounds labeled "endo" and "exo" are actually identical molecules. They are one and the same. But that molecule is also considered a meso compound because it has chiral centers yet is achiral overall. (There is a plane of symmetry within the molecule.) You could form a diastereomer of this compound by changing the configuration at one stereocenter.

[@emilyandrews7457]

You’re carrying me through Ochem II rn😭

[@Leah4sci]

Aww I'm so glad to help you through!

[@man-yinleung8990]

When the dienophile is cis, the exo and endo products are meso compound isn't it ?

[@Leah4sci]

Great question! Yes, you are correct. For help with more like this, I recommend joining the organic chemistry study hall. Details: leah4sci.com/join or contact me through my website leah4sci.com/contact/

[@saravalencia6857]

Hi Leah, in the beginning of the video you quickly run by some of the previous videos. However, in 0:12 , there is an example shown where the dienophile has 3 oxygens attached, one in the middle, and the other two attached on either sides via a double bond. I tried looking for this example in the two previous videos but can't locate it, so I was wondering if you made another video that includes this problem.

[@Leah4sci]

Thank you for pointing this out! I skimmed the previous two videos as well, and you're correct. It's not found in either of those videos. It's possible that particular image was pulled from one of my longer Study Hall videos, which you can access if you join the Organic Chemistry Study Hall. Details: leah4sci.com/join or contact me through my website leah4sci.com/contact/

[@MdFaisal-ol3jv]

Knoevenagel condensation reaction please.

[@Leah4sci]

I've never heard of that reaction

[@Leah4sci]

Thank you. Sounds like you know the reaction now, so all good?

[@MOHAMMADMURSALEEN-eq6ir]

you are the best

[@Leah4sci]

Thank you so much :)