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Topic: is this elimination?  (Read 8746 times)

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Offline slimlingsaucer

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is this elimination?
« on: September 05, 2007, 05:18:32 AM »
CH3CH2CH2Br + LiAlH4 ---) ? e2??

Offline organic help

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Re: is this elimination?
« Reply #1 on: September 05, 2007, 07:24:56 AM »
Well, LAH (LiAlH4) is a strong base, and your substrate is a primary alkyl halide and definitely capable of E2, so i would say that you are seeing E2 out of this reaction.  Any thoughts from anyone else?

Offline choongaloonga

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Re: is this elimination?
« Reply #2 on: September 05, 2007, 07:39:43 AM »
But what comes from this reaction?Maybe LiAlH4 gives H and takes Br so it produces alkane and LiAlH3Br or?
iF IT'S e2 THEN ALKENE SHOULD BE THE PRODUCT..

Offline movies

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Re: is this elimination?
« Reply #3 on: September 05, 2007, 12:17:28 PM »
This is a reduction reaction, not an elimination.  The product would be propane.

Offline Yggdrasil

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Re: is this elimination?
« Reply #4 on: September 05, 2007, 12:21:02 PM »
Could this be thought of something like an SN2 reaction?  The LAH donates a hydride that acts as the nucleophile and the Br is the leaving group.

Offline slimlingsaucer

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Re: is this elimination?
« Reply #5 on: September 05, 2007, 01:45:16 PM »
I don't see how this could be elimination because the base should take Hydrogen and how is LiAlH4 capable of that?
SN2 seems to be the better solution..H reacts like Nucleophile and bonds with C and Br is the leaving group..
Well, LAH (LiAlH4) is a strong base, and your substrate is a primary alkyl halide and definitely capable of E2, so i would say that you are seeing E2 out of this reaction.  Any thoughts from anyone else?
How?could you explain..what products could it give if it is e2?

Offline macman104

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Re: is this elimination?
« Reply #6 on: September 05, 2007, 03:07:25 PM »
It's not E2.  Like Movies said, LiAlH4 reduces primary alkyl halides to alkanes

Hey, look publications!

Offline choongaloonga

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Re: is this elimination?
« Reply #7 on: September 06, 2007, 07:07:11 AM »
Could this be thought of something like an SN2 reaction?  The LAH donates a hydride that acts as the nucleophile and the Br is the leaving group.
Yes I think it can.

Offline movies

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Re: is this elimination?
« Reply #8 on: September 06, 2007, 04:26:44 PM »
Could this be thought of something like an SN2 reaction?  The LAH donates a hydride that acts as the nucleophile and the Br is the leaving group.
Yes I think it can.

The results of the paper linked by macman suggest that the mechanism may in fact proceed through radical intermediates.  It's a good read!

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