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Topic: Bromination  (Read 6109 times)

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Offline Retsu Unohana

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Bromination
« on: August 16, 2009, 10:10:48 AM »
Does bromination of a cyclic compound occur the same way as a simple aliphatic compound?

For example, if you brominate 1-tertbutyl-cyclohexane, do you get 1-bromo-1-tertbutyl-cyclohexane? Or do you get the bromine elsewhere on the ring?

Offline azmanam

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Re: Bromination
« Reply #1 on: August 16, 2009, 10:15:42 AM »
depends on what the conditions are.  HBr?  Br2?  NBS?  light?  heat?
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Offline Retsu Unohana

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Re: Bromination
« Reply #2 on: August 16, 2009, 10:38:20 AM »
I think bromination uses Br2 every time. In that case, wouldn't there just be a single major product?

Offline azmanam

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Re: Bromination
« Reply #3 on: August 16, 2009, 12:57:06 PM »
Not necessarily, but I misread the question at first. I agree with you that Br2 will be the conditions here. In that case, I agree with your answer in op.  Why do you think the Br will add there?
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Offline Retsu Unohana

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Re: Bromination
« Reply #4 on: August 16, 2009, 01:04:14 PM »
Well tertiary carbocations are the most stable, so I believe the bromine will add there. I'm just thinking whether or steric hindrance by the t-butyl will affect the reaction.

Offline azmanam

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Re: Bromination
« Reply #5 on: August 16, 2009, 01:06:52 PM »
Quote
tertiary carbocations are the most stable

True, but there will not be a carbocation intermediate in this mechanism.  Start here:
http://www.cem.msu.edu/~reusch/VirtTxtJml/funcrx1.htm#halogen

Quote
I'm just thinking whether or steric hindrance by the t-butyl will affect the reaction.

eh, maybe.  I think the major product will be the one you describe.
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Offline Retsu Unohana

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Re: Bromination
« Reply #6 on: August 16, 2009, 02:24:02 PM »
^ Sorry, I meant tertiary radical.

But thanks for confirming my answer.

Offline bacrcr

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Re: Bromination
« Reply #7 on: August 18, 2009, 10:39:53 PM »
different reaction conditions may results different products ,especially for this sensitive
reaction

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