Topic: Draw the major organic product of the following? (Read 18426 times)

discodermolide · « **Reply #15 on:** March 25, 2013, 09:40:46 PM »

So which ester undergoes a Claisen condensation? And why?

theanonymous · « **Reply #16 on:** March 25, 2013, 09:45:13 PM »

Quote from: discodermolide on March 25, 2013, 09:34:49 PM

Sorry I was referring to one of your previous posts. The images are a bit small on my screen and with my eyesight!
Let me think about number 6.

Ok!

theanonymous · « **Reply #17 on:** March 25, 2013, 09:47:03 PM »

Quote from: discodermolide on March 25, 2013, 09:40:46 PM

So which ester undergoes a Claisen condensation? And why?

The first one because on the left, there are 2 alpha H protons that can be attacked by a base to make that carbon nucleophilic, which will then be able to attack the second equivalent of the ester.

discodermolide · « **Reply #18 on:** March 25, 2013, 09:52:15 PM »

I think it is the first one. The reason the second one doesn't react is probably steric congestion. The anion of the second one is on a tertiary carbon, and to react it must produce a sterically crowded quaternary carbon. This is certainly not likely.

theanonymous · « **Reply #19 on:** March 25, 2013, 09:55:03 PM »

Quote from: discodermolide on March 25, 2013, 09:52:15 PM

I think it is the first one. The reason the second one doesn't react is probably steric congestion. The anion of the second one is on a tertiary carbon, and to react it must produce a sterically crowded quaternary carbon. This is certainly not likely.

Sooo...for part A, i do the Claisen reaction for the first ester?

discodermolide · « **Reply #20 on:** March 25, 2013, 09:56:44 PM »

Yes.

theanonymous · « **Reply #21 on:** March 25, 2013, 10:00:47 PM »

Quote from: discodermolide on March 25, 2013, 09:56:44 PM

Yes.

I submitted this...

1/3 submissions...and it's wrong...
aklbfsajksdfkljdfsjkn

I don't even know what to say.

discodermolide · « **Reply #22 on:** March 25, 2013, 10:02:21 PM »

That's what I would say is correct.
CC(C(CC)=O)C(OC1CCCCC1)=O

theanonymous · « **Reply #23 on:** March 25, 2013, 10:03:23 PM »

Quote from: discodermolide on March 25, 2013, 10:02:21 PM

That's what I would say is correct.

They marked it as wrong though

discodermolide · « **Reply #24 on:** March 25, 2013, 10:09:36 PM »

Now I am at a loss as to what they want here.
These questions are somewhat misleading as to the reagents used. The acid work up should just protonate everything. I wonder if the acid work up is also hydrolysing the ester in the product to give the acid which then decarboxylates?

Meaning that
O=C(CC)CC

is the product they want?

theanonymous · « **Reply #25 on:** March 25, 2013, 10:13:07 PM »

Quote from: discodermolide on March 25, 2013, 10:09:36 PM

Now I am at a loss as to what they want here.
These questions are somewhat misleading as to the reagents used. The acid work up should just protonate everything. I wonder if the acid work up is also hydrolysing the ester in the product to give the acid which then decarboxylates? Meaning that

is the product they want?

I'll try it. But I have no idea what they want either...
I mean if you can't figure it out then my class's average for this HW assignment is gonna be really really low

Because I doubt anyone else in my class can figure this out on their own.

discodermolide · « **Reply #26 on:** March 25, 2013, 10:17:54 PM »

I can figure it out but as I said the questions are misleading and finding out exactly what they want is the hard part.
As I wasn't in your class I can't really comment on the material you were given.
I'm sorry I don't seem to be much use tonight

theanonymous · « **Reply #27 on:** March 25, 2013, 10:18:16 PM »

Wait...I found this in my teachers lecture notes

Is that what we have to do?

theanonymous · « **Reply #28 on:** March 25, 2013, 10:20:05 PM »

Also, I found this on Yahoo Answers...it's very similar to the one I'm given..

http://answers.yahoo.com/question/index?qid=20090414141221AAsklSv

What does C6H5-O-C(=O)-CH(CH3)-C(=O)C2H5 look like?

discodermolide · « **Reply #29 on:** March 25, 2013, 10:22:30 PM »

You mean they want the enolate as the product?
O=C(CC)/C(C)=C(O)/OC1CCCCC1

This is also in equilibrium with the keto form and the other enolate.

Topic: Draw the major organic product of the following? (Read 18426 times)

discodermolide

Re: Draw the major organic product of the following?

theanonymous

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discodermolide

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discodermolide

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