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Topic: Diels-Alder Exercise corrections please  (Read 1698 times)

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Offline SpinzTronics

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Diels-Alder Exercise corrections please
« on: July 11, 2014, 01:23:52 AM »
Hi, I am studying for my exam and I found these exercises (attached picture) for which I don't have the solutions to check my answers and correct them. I would appreciate if you guys could take a look at them and let me know if I am incorrect, also let me know why please...

These are the concepts I have been following for Diels-Alder:
1) the diene is above the pi group of the dienophile, this gives rise to the endo product AND/OR the dienophile will always retain the "into the page" stereochem while the diene may be either away/into the page (original outward substituents) or out/up (original substituents poiting towards one another).
2) if the pi group is pointed away, or not underneath, then it will give rise to the exo product

So, I sometimes get confused about these, and the positions of the substituents like in part b) how do you know if both carbonyl groups (trans) are facing the same way, or opposite to each other? :o

I greatly appreciate your help in advance!!!

Online mjc123

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Re: Diels-Alder Exercise corrections please
« Reply #1 on: July 11, 2014, 09:11:12 AM »
Can't you at least post the picture the right way up? Come on, meet us half way!

Offline orgopete

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Re: Diels-Alder Exercise corrections please
« Reply #2 on: July 12, 2014, 07:08:21 PM »
Luckily for me, I'm looking at these on a tablet, so I just rotated it. Only e) has exo and endo. Check stereochemistry of sp2 carbons.
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