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Topic: organic chem mechanism nucleophilic addition  (Read 1846 times)

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Offline girl101

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organic chem mechanism nucleophilic addition
« on: February 09, 2016, 06:29:39 PM »
hi i am a bit puzzled as to what to do for the last question especially.  im not sure if its supposed to be a radical reaction with c-br. please help see attachment . help greatly appreciated

Offline clinz63

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Re: organic chem mechanism nucleophilic addition
« Reply #1 on: February 09, 2016, 09:16:59 PM »
I think it would be a rearrangement of the Br to the other equally stable but less hindered tertiary carbon. So it will become 1-bromo-4-ethyl-1-methylcyclohexane.

Online Babcock_Hall

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Re: organic chem mechanism nucleophilic addition
« Reply #2 on: February 10, 2016, 10:46:34 AM »
Can you provide a little bit more of your thinking?  Suppose we exclude radical mechanisms.  Can you think of any way to turn E into F?

Offline clinz63

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Re: organic chem mechanism nucleophilic addition
« Reply #3 on: February 11, 2016, 01:28:13 AM »
My bad. It didn't say it had to react. It just asked what happens to the compound when C-Br is broken homolytically. So you're just left with a radical. A lone electron in place of the Br. The emphasis here is if you know which arrows to draw since the reaction is homolytic.

The hint for the transformation of E to F is question (ii). Which is the most stable? 1°, 2° or 3° carbocation?

Online Babcock_Hall

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Re: organic chem mechanism nucleophilic addition
« Reply #4 on: February 11, 2016, 08:52:14 AM »
@OP,
My previous remark was solely about the transformation from E to F (I may not have read your question as carefully as I should have).  Are we focusing on whole question or just the last part (v)?  If the latter, what are the definitions of homolytic cleavage vs. heterolytic cleavage?  I think you are on the right track, but it would be helpful for you to show what you think will happen.  It sounds to me as if the question is only about a single step.

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