[mana]

hi all
in the reaction below an acetophenone has reacted with dimethyl succinate.  my problem is how only on of the ester functional group convert to acid carboxylic not both of them (at the second process)
is this reaction possible?

[mana]

hi all
in the reaction below an acetophenone has reacted with dimethyl succinate.  my problem is how only on of the ester functional group convert to acid carboxylic not both of them (at the second process)
is this reaction possible?

I guess the question must have a mistake isn't it? because an ester can not convert to acid carboxylic with out water (hydrolysis)
I think I should add water at the first step of reaction

[sjb]

Look into variations of the Claisen condensation.

[mana]

Look into variations of the Claisen condensation.

you mean this?

[kriggy]

I suppose you could run the cyclization by just heating it with acid like H2SO4 or something. Then if if works, you can re-esterify the other COOH

[rolnor]

Is not the ketone alpha-protons more acidic than the esterprotons? In that case the first step would be very different.

[pgk]

Why don’t you try to draw the mechanism of the reaction?
Then, you can see how the one carboxylic group is formed, without hydrolysis.

[mana]

Is not the ketone alpha-protons more acidic than the esterprotons? In that case the first step would be very different.

the proton on malonate is btw two electron withdrawing group so I think the proton of malonate is more acidic than cetophenone

[mana]

Why don’t you try to draw the mechanism of the reaction?
Then, you can see how the one carboxylic group is formed, without hydrolysis.

I think in the first step as I have drawn in the last reaction first the proton of diester must be removed and the anion will attack the carbonyl group of ketone, the cyclization will form a lactone is it wrong?

[rolnor]

But its not malonic ester, its succinic?

[mana]

But its not malonic ester, its succinic?

yes you are right I have written the name of di ester wrong, but what about the mechanism? is it wrong either?

[pgk]

Yes, it is right. This reaction is named “Stobbe Condensation”.
J. Am. Chem. Soc., 1950, 72(1), 514–517
DOI: 10.1021/ja01157a133
http://pubs.acs.org/doi/abs/10.1021/ja01157a133?journalCode=jacsat

[mana]

Yes, it is right. This reaction is named “Stobbe Condensation”.
J. Am. Chem. Soc., 1950, 72(1), 514–517
DOI: 10.1021/ja01157a133
http://pubs.acs.org/doi/abs/10.1021/ja01157a133?journalCode=jacsat

thanks