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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: osker246 on May 27, 2010, 09:37:09 PM

Title: What is the product of this reaction?
Post by: osker246 on May 27, 2010, 09:37:09 PM

Hello,

I've come here to seek out some assistance to a question I had answered wrong on an exam. Our instructor is allowing us to perform corrections to earn some points back. But this means I need to understand where I went wrong and know the correct answer. I have uploaded 2 PDF files, one containing the question to the problem and the other containing the mechanism I came up with. I would deeply appreciate it if somebody would help me out on this, and if it is wrong can you explain where I went wrong? Thank you!

Title: Re: What is the product of this reaction?
Post by: Doc Oc on May 27, 2010, 09:50:17 PM

What you've written is all correct, but it needs to go one step further.  Can you see it?  Hint: acetoacetate.

Title: Re: What is the product of this reaction?
Post by: osker246 on May 27, 2010, 10:15:37 PM

 ???

I don't know...I'm not sure if I learned this or not...

Is acetoacetate a side product of the reaction? Thank you for responding as well.

Title: Re: What is the product of this reaction?
Post by: Doc Oc on May 28, 2010, 12:24:54 AM

I'm making an assumption here that you've learned reactions with malonic ester, correct?  What is it that they do that's special?

Title: Re: What is the product of this reaction?
Post by: osker246 on May 28, 2010, 02:02:27 AM

Yes we have learned reactions with malonic ester, forgive me I am a little slow when It comes to thinking these kind of things through. The only two things I can think of having to do with malonic ester at the moment would possibly be decarboxylation and then tautomerization of the enol resulting from decarboxylation. But in order for this to occur this would require heat, which it is not specified in the problem. My second thought would be the removal of the acidic hydrogen between the carbonyl groups by water, thus making the the overall molecule act as a nucleophile and possibly reacting with ethanol to add an akyl group. But then again this would all be occurring in acid conditions, which I don't see happening. So my best guess at this moment would be decarboxylation?

Title: Re: What is the product of this reaction?
Post by: Doc Oc on May 28, 2010, 08:33:12 AM

I'm willing to bet that's what your prof is looking for (although you're right, they usually do specify heat, so if that's what he wanted then it's also his fault for not being thorough in writing the question).

Title: Re: What is the product of this reaction?
Post by: osker246 on May 29, 2010, 02:01:27 AM

Well I spoke to my professor and I was told if heat is not stated, then I should not assume that it will under go decarboxylation. So it seems as if the product I originally constructed is the correct answer. I appreciate the help J-bone. Thank you.

Title: Re: What is the product of this reaction?
Post by: Doc Oc on May 29, 2010, 09:42:45 PM

No problem, happy to help.