OChem and Destroyer Questions

[omgdats]

Hi,

I have a couple of questions regarding the ochem destroyer 2009 #19 and 24.

19 - for the NMR, why is it that the structure gives a quartet, singlet, and triplet? i thought that the number of signals is n+1, so it would be quartet, triplet, and quartet.

24 - according to destroyer, doing an alkylation results in a rearrangement, but how does that happen?

lastly, is NR2 a ring activator or deactivator? kaplan says its an activator but destroyer says deactivator.

thanks!

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[nze82]

Hi,

I have a couple of questions regarding the ochem destroyer 2009 #19 and 24.

19 - for the NMR, why is it that the structure gives a quartet, singlet, and triplet? i thought that the number of signals is n+1, so it would be quartet, triplet, and quartet.
Don't have the book with me, so I wouldn't be able to help you unless you tell me what the question is asking for.
24 - according to destroyer, doing an alkylation results in a rearrangement, but how does that happen?
This is a general and an inaccurate statement. Not all alkylation reactions result in rearrangement. The only time that alkylation is accompanied by rearrangement is when the alkyl group is transferred as a carbocation, carboanion, or a free radical. Obviously, the rearrangement can occur under such circumstance to make these intermediates more stable.
lastly, is NR2 a ring activator or deactivator? kaplan says its an activator but destroyer says deactivator.
NR2 is definitely a ring ACTIVATOR, because N posses a lone pair of electrons, which it could use to add to the electron density of the ring and make the ring more reactive toward EAS (Electrophilic Aromatic Substitution) reactions. Perhaps you're mistaking NR2 (Activating) with NO2, which is a deactivating group.
thanks!

Hope this helps!

 

[omgdats]

Hope this helps!

oh..for the NMR, the answer is ethyl acetate and the proton NMR spectrum shows a quartet at 4ppm, a singlet at 2ppm, and triplet at 1ppm.

i should have been more specific. the destroyer states that rearrangement occurs if you add on 3 carbons or more in a linear fashion. i just didnt know that rearrangement could occur for carboanion.

also i just checked the answer..i read it wrong. the destroyer put NR2H+ is a deactivator.

thanks for your help

 

[nze82]

Hi,

I have a couple of questions regarding the ochem destroyer 2009 #19 and 24.

19 - for the NMR, why is it that the structure gives a quartet, singlet, and triplet? i thought that the number of signals is n+1, so it would be quartet, triplet, and quartet.

24 - according to destroyer, doing an alkylation results in a rearrangement, but how does that happen?

lastly, is NR2 a ring activator or deactivator? kaplan says its an activator but destroyer says deactivator.

thanks!

Hope this helps!