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Topic: Terminal Alkenes  (Read 11907 times)

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Offline Aznhmonglor

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Terminal Alkenes
« on: March 09, 2009, 07:16:21 PM »


I know what happens in B and C but I am stuck on A. What does the NaOH do to the Br?

Offline azmanam

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Re: Terminal Alkenes
« Reply #1 on: March 09, 2009, 07:29:54 PM »
Same thing it does in B... just a different regioisomer.  There's a rule governing these eliminations...
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Offline Aznhmonglor

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Re: Terminal Alkenes
« Reply #2 on: March 09, 2009, 07:37:00 PM »
Okay so I did what I did to B on A and got this but was not correct.



What did I do wrong? Was it because the NaOH cannot attack the carbon center which already has 4 bonds?

Offline azmanam

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Re: Terminal Alkenes
« Reply #3 on: March 09, 2009, 07:42:38 PM »
oh.  then you got B wrong.  They're all eliminations.
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Offline Aznhmonglor

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Re: Terminal Alkenes
« Reply #4 on: March 09, 2009, 07:45:39 PM »
No I got B right. This is what B came out to being.


Offline azmanam

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Re: Terminal Alkenes
« Reply #5 on: March 09, 2009, 07:47:47 PM »
then none of them give you the target product.  to get the target product, you must do an elimination.
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Offline Aznhmonglor

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Re: Terminal Alkenes
« Reply #6 on: March 09, 2009, 07:50:36 PM »
I am so sorry azman I forgot to include this part.

"Synthesizing terminal alkenes by the following routes is problematic because the terminal alkene shown in the box is only a minor product if formed at all."

So that does mean that all the reactions will not give me the target product thats what the professor wanted us to know. So for A would it eliminate the Br and form a double bond like so?


Offline azmanam

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Re: Terminal Alkenes
« Reply #7 on: March 09, 2009, 08:00:56 PM »
imho, yes.  You miiiiight get some E1, but that will be the major pdt of A.
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Offline azmanam

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Re: Terminal Alkenes
« Reply #8 on: March 09, 2009, 08:01:23 PM »
Knowing why you got a question wrong is better than knowing that you got a question right.

Offline Aznhmonglor

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Re: Terminal Alkenes
« Reply #9 on: March 09, 2009, 08:03:05 PM »
Thanks much. I was correct.

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