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Topic: Addition of HBr to an Alcohol with an Alkene  (Read 2636 times)

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Offline Cooper

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Addition of HBr to an Alcohol with an Alkene
« on: February 06, 2013, 04:48:13 PM »
Hi,

I do a lot of syntheses on paper for my orgo class and I come across this predicament a lot.

If I am adding HBr to an alcohol that also has an alkene, which one will the HBr react with? Will it react with both in varying amounts so that you get mixed products? I am assuming this is only a question when the carbon that the alcohol is on is tertiary, because it is an Sn1 reaction.

Thanks!

Also, on a non-chem note, is there anywhere on the website where you can view all the threads you are subscribed too?
~Cooper :)

Offline Hunter2

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Re: Addition of HBr to an Alcohol with an Alkene
« Reply #1 on: February 06, 2013, 06:03:24 PM »
The double bond is easier to react.  But it depends also on the side groups.

Offline Arkcon

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Re: Addition of HBr to an Alcohol with an Alkene
« Reply #2 on: February 06, 2013, 06:05:49 PM »
Also, on a non-chem note, is there anywhere on the website where you can view all the threads you are subscribed too?

You mean like this:  http://www.chemicalforums.com/index.php?action=profile;area=showposts;u=141795  Just click the username.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline Cooper

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Re: Addition of HBr to an Alcohol with an Alkene
« Reply #3 on: February 06, 2013, 06:58:58 PM »
@Hunter, thanks :) Do you know why it's easier to react?

@Arkcon, THANK YOU!!
~Cooper :)

Offline souro10

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Re: Addition of HBr to an Alcohol with an Alkene
« Reply #4 on: February 07, 2013, 01:08:30 AM »
I think acid-base reactions are the fastest to occur. Donating the lone pair on oxygen is both faster and energetically more favored, than breaking the double bond. Note that in either case there shall be a tertiary cation intermediate.

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