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Topic: Synthesis Roadmap help  (Read 9782 times)

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Offline magician4

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Re: Synthesis Roadmap help
« Reply #15 on: August 13, 2013, 05:38:04 PM »
yes, those are the two possible products for a non-conjugated diene system

take a look at the mechanism with Bird (follow my link above), i.e try to decide whether your substituents are pushing electron density or withdrawing it from the ring (and, hence, the outcome here)


regards

Ingo
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Offline lineskier22

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Re: Synthesis Roadmap help
« Reply #16 on: August 13, 2013, 05:51:41 PM »
yes, those are the two possible products for a non-conjugated diene system

take a look at the mechanism with Bird (follow my link above), i.e try to decide whether your substituents are pushing electron density or withdrawing it from the ring (and, hence, the outcome here)


regards

Ingo

I think it's pushing because the double bonds have been moved/pushed to provide stability. A carbocation is not hoarding electrons either (if that would even happen here).
So my answer is the first molecule (double bond on the left and right verticals) to give a H where the methyls connect.

Looking through my notes I found a few examples with the double bonds at the carbons with a methyl. I'm second guessing myself now.. I think it's the second now.
« Last Edit: August 13, 2013, 06:29:59 PM by lineskier22 »

Offline lineskier22

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Re: Synthesis Roadmap help
« Reply #17 on: August 13, 2013, 08:16:11 PM »
My thought process for the next step.. I'm pretty sure the ring breaks due to ozonolysis and forms a chain like my answer.

Offline KrCo

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Re: Synthesis Roadmap help
« Reply #18 on: August 14, 2013, 01:39:02 AM »
Yes, this is an example for the ozonolysis; it is right that the ring breaks, but in an other way...
The ozone is like scissors of the double bonds - check just the 1st reaction here:
http://en.wikipedia.org/wiki/Ozonolysis
I hope, it helps  ;)


Offline Archer

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Re: Synthesis Roadmap help
« Reply #19 on: August 14, 2013, 02:16:18 AM »
You need to study the mechanism and intermediate species for the reaction(s) first, then apply it to your substrate. This is the only way that you will get the right answer.
“ I love him. He's hops. He's barley. He's protein. He's a meal. ”

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Offline lineskier22

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Re: Synthesis Roadmap help
« Reply #20 on: August 14, 2013, 08:13:18 AM »
So I asked my prof. And he basically shot me down with no help cause it's part of the final.

So I made a 4 carbon chain and added =O to carbon 1 and 2, trans to each other. I asked a fellow student and she said that seems right...

Offline Archer

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Re: Synthesis Roadmap help
« Reply #21 on: August 14, 2013, 08:51:26 AM »
This is a good lesson in not asking your fellow students for advice, please incldue your structures in your answer as it helps us to see whether you are right or not. In this case you are not, it will not form a 1,2-diketone.

Look at this ozonolysis
 
taken from
http://www.masterorganicchemistry.com/2013/04/23/alkene-reactions-ozonolysis/

This is not disimilar to your substrate, yours is cyclic but this shows what kind of products you should be getting from an ozonolysis reaction.
“ I love him. He's hops. He's barley. He's protein. He's a meal. ”

Denis Leary.

Offline lineskier22

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Re: Synthesis Roadmap help
« Reply #22 on: August 14, 2013, 10:45:53 AM »
If I'm understanding it right I will have two products with 2 Carbons each. I have examples like that but since it was cyclic I got a little lost

Offline Archer

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Re: Synthesis Roadmap help
« Reply #23 on: August 14, 2013, 11:21:14 AM »
No, your product has the formula C4H6O2 (as per your images in the opening post).

Your starting material has the formula C8H12

So in essence you are breaking the molecule into two identical molecules, each with two oxygens. Do you think these will be ketones, alcohols, esters, ethers, aldehydes, carboxylic acids?
“ I love him. He's hops. He's barley. He's protein. He's a meal. ”

Denis Leary.

Offline lineskier22

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Re: Synthesis Roadmap help
« Reply #24 on: August 14, 2013, 12:36:36 PM »
...

Offline Archer

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Re: Synthesis Roadmap help
« Reply #25 on: August 14, 2013, 01:06:22 PM »
I am very sorry about this but it is clear from what you have just posted that you have not fully understood a lot of the help that has been provided. Please read through the posts again and check the links that have been indicated by everyone who has contributed to this thread.

I would like to provide you with all of the answers to this assignment but ethically I cannot do this. It would also constituted plagiarism on your part (don't forget this is an open forum and your Prof is able to view it).

I can give one last piece of help and then I am afraid that I have to put all of my attention into something else.

The reaction that leads to compound E is a Michael Addition http://en.wikipedia.org/wiki/Michael_reaction, this does not give the molecule that you have drawn it gives something else.

P.S. It would not be a good idea to submit the work telling the prof that the first step would not work experimentally unless you are able to explain, in detail, why it wouldnt work (don't just take my word for it).
“ I love him. He's hops. He's barley. He's protein. He's a meal. ”

Denis Leary.

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