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Topic: Kind of confused... I think my professor has made a mistake.  (Read 1840 times)

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Offline Fischer

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Kind of confused... I think my professor has made a mistake.
« on: December 12, 2013, 09:33:14 AM »
Hey guys.

So my professor was doing some problems on the board,

He did the following;

Cyclohexane + Na  :rarrow: cyclohexane (secondary carbocation) + NaH

I am very confused about this... He formed a secondary carbocation from adding Na to cyclohexane. I did not ask him in class as I just realized what he did when reading through my notes. Is this even possible.

Offline Fischer

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Re: Kind of confused... I think my professor has made a mistake.
« Reply #1 on: December 12, 2013, 09:53:40 AM »
Any ideas guys?

Offline AlphaScent

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Re: Kind of confused... I think my professor has made a mistake.
« Reply #2 on: December 12, 2013, 09:57:51 AM »
I would think that this reaction would not proceed.  I rinse my sodium before using it with hexanes all the time and there is no reaction.  I just do not think the protons are acidic enough.  I would email and ask him.  I do not think that is good theory to teach.  I could be wrong due to some interaction I am not taking into account when it is in the chair conformation.  But like I said, do not believe there will be a reaction.  He could just be doing as theory, not practical. 

Ask him..Id like to know what he says.
If you're not part of the solution, then you're part of the precipitate

Offline Fischer

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Re: Kind of confused... I think my professor has made a mistake.
« Reply #3 on: December 12, 2013, 10:01:55 AM »
Yeah I'm going to ask him... Unless as you stated, we are not taking something into account but I highly  doubt that.

Offline AWK

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Re: Kind of confused... I think my professor has made a mistake.
« Reply #4 on: December 12, 2013, 10:43:20 AM »
May be your teacher thought about cyclohexanol?
AWK

Offline Dan

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Re: Kind of confused... I think my professor has made a mistake.
« Reply #5 on: December 12, 2013, 02:38:18 PM »
No, it's nonsense; CyH + Na :rarrow: Cy+ + NaH is not even balanced.

The reaction with cyclohexanol is CyOH + Na :rarrow: CyONa + 1/2 H2

He's made a mistake, you should ask him to clarify.
« Last Edit: December 12, 2013, 06:48:10 PM by Dan »
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Offline orgopete

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Re: Kind of confused... I think my professor has made a mistake.
« Reply #6 on: December 12, 2013, 06:15:22 PM »
Often we can guess what might have been meant, even when there is an error. In this case, I can't even do that. Sodium metal is an electron donor and the net result shows sodium has donated its electron, but the recipient ends up with a positive charge. This is clearly an error (assuming the notes are correct). A simple test, the net charges on each side of the arrow must balance. In this case, they do not.
« Last Edit: December 12, 2013, 09:55:58 PM by orgopete »
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