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Topic: converting a halide to hydroxyl  (Read 5160 times)

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Offline Baerchen

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converting a halide to hydroxyl
« on: June 04, 2010, 08:21:14 AM »
Hi there,

I seem to have problems identifying how to convert a primary halogen to a hydroxyl group. I thought it would be straightforward but it seems going the other way is the more common reaction.
Ideally I'd like to convert the halide to hydroxyl, aldehyde or carboxylic ester so if I can get directly to any of these I would be happy.
I am thinking about the Williamson-ether synthesis to make an ether and go from there.

I appreciate any suggestions of reagents or even some better search terms to help me with.

Thank you!

Offline Doc Oc

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Re: converting a halide to hydroxyl
« Reply #1 on: June 04, 2010, 08:26:28 AM »
Depending on your alkyl halide this can be a tricky reaction.  The most obvious solution would be to add NaOH, but you risk not only getting the substituted product, but also the eliminated product.

If you want to convert it to a carboxylic acid you could try turning your alkyl halide into a Grignard and reacting it with CO2, although that also depends on the complexity of your starting material.

Offline Baerchen

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Re: converting a halide to hydroxyl
« Reply #2 on: June 04, 2010, 08:52:24 AM »
Thanks for your answer, J-bone.
I do indeed have a complicated structure, so I will research which of these methods (if any) will be suitable.
Thanks again for giving me some direction!

Offline stewie griffin

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Re: converting a halide to hydroxyl
« Reply #3 on: June 04, 2010, 09:28:12 AM »
The Kornblum oxidation will give you the aldehyde...
http://en.wikipedia.org/wiki/Kornblum_oxidation

Offline azmanam

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Re: converting a halide to hydroxyl
« Reply #4 on: June 04, 2010, 12:11:39 PM »
also, careful with the Grignard + CO2 route, you'll extend the carbon chain by 1.

You could use sodium acetate as your nucleophile, instead of sodium hydroxide. 
Knowing why you got a question wrong is better than knowing that you got a question right.

Offline Doc Oc

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Re: converting a halide to hydroxyl
« Reply #5 on: June 04, 2010, 12:22:11 PM »
also, careful with the Grignard + CO2 route, you'll extend the carbon chain by 1.

You could use sodium acetate as your nucleophile, instead of sodium hydroxide. 
Oops!  Good catch, azmanam!

Offline OC pro

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Re: converting a halide to hydroxyl
« Reply #6 on: June 04, 2010, 03:06:42 PM »
One could also eliminate the halide to afford the olefine (only when there is no possibility for isomerisation) which could then underwent hydroboration to the primary alcohol,

Offline Baerchen

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Re: converting a halide to hydroxyl
« Reply #7 on: June 05, 2010, 04:41:53 AM »
Great, thanks for all of your suggestions. The Kornblum oxidation seems to suit my needs and I hadn't heard of it before so thanks! I've found some recent reports on this type of reaction that sound promising. I'll report back with my results! Thanks again for your help

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