[nocrown]

I have a question asking me to make C10H18O2 from the Ketone-Ester found below. I have a few questions regarding this.

So first reaction takes place with ethyl magnesium bromide which I believe is a very strong base. This leads me to think Acylation of the Ketone. If it the Ketone didn't have the CO-OCH3 at the end I would have made something like I did below but I don't know what to do now that there is OCH3 instead of CH3. Would it become cyclohexene with branching sides?

(R = the rest of the carbon chain)

[nocrown]

Hi. I want to react

gamma-Butyrolactone with H2O/H+

I know that a esterification of a hydroxyl-carboxylic acid will get gamma-Butyrolactone with H2O. I was wondering is the reaction above simply a reverse of the esterification.
 
In that case I would have HO-CH2-CH2-CH2-CO-OH as my product?

[orgopete]

Two questions, how many carbons are in the starting material (ignore the OCH3).

Which is more reactive, an ester or a ketone?

[orgopete]

Is this the same problem as your other post?

[Arkcon]

nocrown:, I hope you don't mind my merging your two posts, it seems like they would build off each other.  Because this is a learning forum, I hope you'll provide some theories as to what you think would would happen, and will share with us some info you have, like orgopete: asked.

Hi. I want to react

gamma-Butyrolactone with H2O/H+

This is a pro-drug of abuse, and we don't don't give specific answers to questions involving those.  The function groups in question will likely react the same for similar carbon chains, so you should be able to learn without that specific source.

[nocrown]

Hi. I want to react

gamma-Butyrolactone with H2O/H+

This is a pro-drug of abuse, and we don't don't give specific answers to questions involving those.  The function groups in question will likely react the same for similar carbon chains, so you should be able to learn without that specific source.

Is this really the case? I can't believe my professor would ask such a question, let alone on an assignment for grading. I have never seen basically a "reverse" esterification. If we ignore the current reaction, can esterification of hydroxyl-carboxylic acids be reversed using H2O and H+? Or would this be a completely different reaction. I only can think about esterification at the moment.


@orgopete these are two completely separate problems, although with similar theories

In the first one the original is 8 carbons I believe? If we ignore OCH3. The attached photo was all I received.

I believe that esters are less prone to Nucleophilic attack than the carbonyl group of the ketone. Because most esters are more resonance stabilized? Would this cause the ethyl magnesium bromide to perform a nucleophilic attack on the ketone portion of the compound?

[Arkcon]

Is this really the case? I can't believe my professor would ask such a question, let alone on an assignment for grading ...

Briefly, yes.  Instructors want to use topical examples.  They're focusing on the theoretical, they didn't tell you to do anything illegal.  At least, instructors have been using that argument since Socrates.  And so, as long as we stay theoretical, we feel secure, as well.

[Babcock_Hall]

nocrown,

What is the chemical role that H⁺ plays in esterification?  What role does water play?

[nocrown]

In the first reaction I know we are using a Grignard Reagent. I thought if there wasn't OCH3 I would get something like what I attached.

But this has too many carbons and not enough Oxygen. Basically I think the CH2CH3 portion of the Grignard reagent must attack and "replace" a part of the original compound because it would be a 8 carbon chain attaching to a 2 Carbon chain giving a perfect C10 like the hint in the answer?


EDIT: Ok I got the second one and I'm pretty sure I am correct because the product IS a dangerous drug of abuse. Thanks so much guys. I actually posted the rest of the question so we can check it over. Am I correct in assuming that the LiAlH4 is a reduction of the carboxylic acid into a primary alcohol? with carbon chains with -OH at either end. If this is correct will the last step (H+/heat) be a dehydration of the primary alcohol? If I reduce this do I get a compound with C=C double bonds on each end instead of the C-OH?

[nocrown]

Sorry guys I am really bad at this and I up double posting a lot. Sorry lol.

[orgopete]

No, the Grignard will react with the ketone, just as you have suggested the ester is less reactive (and did not react). This will give an intermediate C11H22O3. If this loses CH3OH, this will give a product of C10H18O2. Since the Grignard product was an alcohol, the net effect in the loss of methanol is an intramolecular transesterification reaction. This can be catalyzed with an acid or base.

[nocrown]

Thanks for the help everyone! After doing some readings I am sure I have solved the questions. I will not be posting them in case someone else as the same assignment.

PS: For anyone wondering the prof made a mistake - the final product in Q2 is C4H8O like I originally thought