[littlejoker]

I'm studying about this and having problem with this exercise:

--(a)--> A --(b)--> B

a. , HCl, H2O
b. 1. LDA 2. MeCl

I suppose the possible structures for A and B are accordingly



The first step: I think firstly an enol is formed and then attack the CH3-(CH+)-CH3. The friedel crafts reaction here I think is quite hard, because of the existence of C=O group.
The second: I think the iPr group there is quite big and so is LDA so the H(alpha) to the carbonyl group might be hard to be picked out, and I choose the "H" on the carbon next to the benzene.
I wonder if my guess is correct or not. Please give me some comments.

[kriggy]

Why would you put methyl on para position against with regards to ketone? Is the hydrogen acidic?

[Vidya]

a) what (a) reagent will give ?
Just review reactions of alkenes ..identify the product of mixing an alkene with HCl and water ...
Now check how it is going to react with ketone .
b) LDA is a strong base ...check reactions of LDA with acidic  alpha hydrogens  to carbonyl group ...
I think this hint will help you.

[littlejoker]

a) what (a) reagent will give ?
Just review reactions of alkenes ..identify the product of mixing an alkene with HCl and water ...
Now check how it is going to react with ketone .
b) LDA is a strong base ...check reactions of LDA with acidic  alpha hydrogens  to carbonyl group ...
I think this hint will help you.

a) Is the product isopropyl chloride? Then I'd suppose that the product would stay the same... Is this reasonable?
b)
Following your hint, I think the structure of B is isn't it?

Why would you put methyl on para position against with regards to ketone? Is the hydrogen acidic?

Actually I thought that the gamma hydrogen is also acidic. Maybe it has the same form as H-CH₂-CH=CH-CH=O ...

[kriggy]

I see. However there is a difference between your molecule and the example you posted in your last post:

[Vidya]

a) Is the product isopropyl chloride? Then I'd suppose that the product would stay the same... Is this reasonable?
b)
Following your hint, I think the structure of B is isn't it?


Actually I thought that the gamma hydrogen is also acidic. Maybe it has the same form as H-CH₂-CH=CH-CH=O ...

a) it will not give you isopropyl chloride ....why did you decide Friedel crfats reaction will not take place?
C=O is not directly on the ring and is not deactivating through resonance ...

[kriggy]

Im going to disagree with the deactivation:

[Vidya]

oh yeah ...there is deactivation through resonance..I just overlooked it