Rotating structure for e2 question

[510586]

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Currently for questions in which we must rotate the single bond, I am drawing a Newman to rotate it accurately. Is it OK to just draw the e2 rxn and then swap a side as a shortcut? Pictured below

 

[DAT Destroyer]

Currently for questions in which we must rotate the single bond, I am drawing a Newman to rotate it accurately. Is it OK to just draw the e2 rxn and then swap a side as a shortcut? Pictured belowView attachment 193545

Your picture was a little difficult to see, this is just a general answer.

Rotation of a Newman projection is fine because rotation will not change the configuration of a molecule. Many students find this a bit baffling. Think of it like this......If I rotate my left sneaker,,,,,,,nor matter the rotation......it is still my left sneaker !!!!

Just remember,,,,If you do E2 elimination the departing groups need to be anti to each other. Only in the anti conformation is the orbital correctly positioned for proper overlap.

The Klein book shows exactly what you are asking very clearly.

Hope this helps!

Dr. Romano

Dr. Romano

 

[510586]

Your picture was a little difficult to see, this is just a general answer.

Rotation of a Newman projection is fine because rotation will not change the configuration of a molecule. Many students find this a bit baffling. Think of it like this......If I rotate my left sneaker,,,,,,,nor matter the rotation......it is still my left sneaker !!!!

Just remember,,,,If you do E2 elimination the departing groups need to be anti to each other. Only in the anti conformation is the orbital correctly positioned for proper overlap.

The Klein book shows exactly what you are asking very clearly.

Hope this helps!

Dr. Romano

Dr. Romano

Thanks for the answer. I'm saying if they were cis (the H and halogen) can we just draw the alkene with conformation as is (removing H and halogen) then switch one of the sides to make it trans? Instead of rotating it?

 

[DAT Destroyer]

Thanks for the answer. I'm saying if they were cis (the H and halogen) can we just draw the alkene with conformation as is (removing H and halogen) then switch one of the sides to make it trans? Instead of rotating it?

Your shortcut seems fine, but make sure you understand the concept!

 

[510586]

Your shortcut seems fine, but make sure you understand the concept!

Oh I do. Thank you! I'll probably still draw it out to be safe not sure how time constrained science is

 

[Typical Average Student]

Your top structure is rotated incorrectly. The left benzene group should be a wedge, not a dash.

 

[510586]

Your top structure is rotated incorrectly. The left benzene group should be a wedge, not a dash.

Are you sure? I got the same answer as the key

 

[Typical Average Student]

Are you sure? I got the same answer as the key

I lied. lol. got it mixed up.

 

[510586]

I lied. lol. got it mixed up.

No problem

 

[DAT Destroyer]

Oh I do. Thank you! I'll probably still draw it out to be safe not sure how time constrained science is

Always glad to help!

Happy 4th !