topscore question

[ippie]

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these are from topscore.

#1. to be aldol "CONDENSATION", we need "heat". but the question doesn't mention "heat". then how can it be dehydrated? I think the answer should be b-hydroxyketone (one step before aldol condensation). but the answer is enone. this question is from topscore test 1 #76

#2. how many signals here? i think four signals.
then, how are they splitted?
H 1 : doublet
H 2 : multiplet (eight)
H 3 : quartet
H 4 : multiplet (five)
Is that right? or other method in symmetry?

#3. same questions as above.
I think two signals.
H 1 : singlet
H 2 : doublet
==> but the answer is two singlets.

#4. topscore doesn't have 3D explanation in PAT section??? I cannot find explanation in PAT!!!

 

[la brat]

these are from topscore.

#1. to be aldol "CONDENSATION", we need "heat". but the question doesn't mention "heat". then how can it be dehydrated? I think the answer should be b-hydroxyketone (one step before aldol condensation). but the answer is enone. this question is from topscore test 1 #76

#2. how many signals here? i think four signals.
then, how are they splitted?
H 1 : doublet
H 2 : multiplet (eight)
H 3 : quartet
H 4 : multiplet (five)
Is that right? or other method in symmetry?

#3. same questions as above.
I think two signals.
H 1 : singlet
H 2 : doublet
==> but the answer is two singlets.

#4. topscore doesn't have 3D explanation in PAT section??? I cannot find explanation in PAT!!!

I remember question 1 from Topscore, and I agree -- it does need heat + acid/base to dehydrate. I put "none of the above" and got it wrong.

 

[Orgodox]

So for #1 I haven't seen the question but keep in mind that when you are near a benzene ring the dehydration happens spontaneously.

For #2 and 3 you made the same mistakes on both. on number three h1 is a singlet. but look at Hs, the other H2s that are next to it are equivalent and wont split each other therefore dont do n+1 rule for 2 its just a singlet.

for number #2 the H4 would only be a triplet ignore the neighboring 4 because its identical and look to 3 and do n+1.