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Topic: Reaction involving KOH/I2  (Read 6580 times)

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Offline Pranav

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Reaction involving KOH/I2
« on: May 05, 2013, 05:37:58 PM »
I have attached the problem. B is the answer I marked but it is incorrect.

I approached it this way. Since KOH/I2 is a good oxidising agent, it oxidises the alcholic group to carbonyl groups, and replaces -CH2I and -CH3 with -OH, as it happens in an iodoform reaction. So the answer is B but the key states that its D. I don't even have the slightest idea about how the reaction will yield D. ???

Any help is appreciated. Thanks!

Offline Dan

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Re: Reaction involving KOH/I2
« Reply #1 on: May 05, 2013, 06:34:32 PM »
Basically you were 2/3 of the way there. D arises from from a rearrangement of B in the presence of KOH. Start by attacking one of the ketone carbonyls with hydroxide, can you see what has happened next?
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Offline Pranav

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Re: Reaction involving KOH/I2
« Reply #2 on: May 06, 2013, 02:19:32 AM »
Basically you were 2/3 of the way there. D arises from from a rearrangement of B in the presence of KOH. Start by attacking one of the ketone carbonyls with hydroxide, can you see what has happened next?

Thanks Dan! :)

First, the OH- attacks the lower carbonyl group (I am referring to the structure shown in B). The phenyl group with -COOH and -NO2 leaves and attacks again at the upper carboyl group forming D. Is this correct?

Offline Dan

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Re: Reaction involving KOH/I2
« Reply #3 on: May 06, 2013, 02:27:03 AM »
Yes, it's called a benzilic acid rearrangement.
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Offline Pranav

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Re: Reaction involving KOH/I2
« Reply #4 on: May 06, 2013, 02:33:30 AM »
Yes, it's called a benzilic acid rearrangement.

Thank you Dan! I think I have this in my notes somewhere. Time to revise them. :P

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