Which one is more downfield?

[muhali3]

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Is carbon 6 or carbon 4 more downfield/deshielded? I'm having a hard time seeing which one will be subject to a more electronegative pull, as they are both one carbon away from a nitrogen.

 

[muhali3]

.

 

[wanderer]

Beyond the scope of the MCAT.

 

[muhali3]

I know, it's an o-chem 2 extra credit problem. I don't know how to make sense of it. w/e

 

[wanderer]

Not the place for homework questions.

 

[muhali3]

I didn't know that, I thought SDNers would want to give me an unfair advantage over all the other students in my class...shame on me for not thinking otherwise.

 

[lorenzomicron]

4 coz its N has more methyl groups.

 

[JSU]

Four is more upfield (shielded) because the 2 nitrogens are closer to it than they are to 6. Hyperconjugation should play a minimal role compared to the inductive effect. IMHO

 

[coach55]

Consider it step by step.
Step 1: Both of the carbons are 1 carbon away from the Nitrogen. So you can't come up with an answer at this point.
Step 2: Both of the carbons away from #4 & #6 carbon are next to a Nitrogen. So you can't come up with an answer at this point either.

Now go further,
Step 3: The nitrogen closest to #6 carbon is attached to one CH3, whereas the nitrogen closest to #4 is attached to two CH3's (being more substituted).

Result: #4 is more deshielded (downfield) than #6.

 

[Caesar]

Not the place for homework questions.

This. Closing.