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Author Topic: Polycarbonyl reactions - caution difficult!  (Read 4952 times)

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Scot

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Polycarbonyl reactions - caution difficult!
« on: November 09, 2006, 10:45:51 AM »

Hi there,

I'm new here, and in desperate need of some help.

I have carried out the following reactions:

Phenanthrene-9,10-dione in water with potassium hydroxide 80*C for 2 hours, then acid work up, to give a product with molecular formula C14H10O3.  From the NMR's this compound is still symmetric, there is a H singlet at 7.19, and with the IR I suspect that there is a carboxylic acid.  Can anyone identify this product?  or have a good guess providing there is a mechanism that supports the guess?

I then tried to oxidise this product back to Phenanthrene-9,10-dione using chromic acid, but I got another new compound.  It is also symmetric, and the C-13 NMR shows that one quaternary carbon have moved downfield to 190ppm, there is a new H singlet at 1.41ppm.

This is an investigation project set to me but you will not be simpily "doing my work for me" since none of the staff in my department can answer this.

If you need any information please email me, or reply and i'll get it up here ASAP.

Scot
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Mitch

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Re: Polycarbonyl reactions - caution difficult!
« Reply #1 on: November 09, 2006, 02:57:23 PM »

Can you post the spectra. It might be easier that way?
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Scot

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Re: Polycarbonyl reactions - caution difficult!
« Reply #2 on: November 10, 2006, 07:35:01 AM »

the spectra are A3 and I only have an A4 scanner, do you want me to just scan them in and try and join them up?
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Ψ×Ψ

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Re: Polycarbonyl reactions - caution difficult!
« Reply #3 on: November 11, 2006, 03:10:12 PM »

What was the intended product of the first reaction with the phenanthrenequinone?
I do have some idea as to what the C14H10O3 might be, but it seems a little weird...
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Scot

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Re: Polycarbonyl reactions - caution difficult!
« Reply #4 on: November 12, 2006, 02:09:24 PM »

I've got an idea too, please share yours!

There was no intended product, just an investigation to see what happened.
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Ψ×Ψ

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Re: Polycarbonyl reactions - caution difficult!
« Reply #5 on: November 12, 2006, 05:10:59 PM »

you first!!!  mine looks pretty strange!
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Scot

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Re: Polycarbonyl reactions - caution difficult!
« Reply #6 on: November 12, 2006, 11:11:57 PM »

well the only molecule I can think of that hass the -COOH is flurenol (9-Hydroxy-9-fluorenecarboxylic acid)

Its symmetrical in one plane, but not the other, do you think that would still return a symmetrical NMR?

Not to mention the fact that I'm a bit confused about the mechanism, breaking and forming C-C with hydroxide?

Other structures that fit the formula are molozonides, ozonlides and diol-ether, which are totally symetrical but don't return a carboxylic acid group.

Scot
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Scot

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Re: Polycarbonyl reactions - caution difficult!
« Reply #7 on: November 13, 2006, 02:26:24 AM »

flurenol is definatly the answer.

The product of the reaction with chromic acid is fluren-9-one, havn't a clue what that mechanism is.

Any ideas?
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Ψ×Ψ

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Re: Polycarbonyl reactions - caution difficult!
« Reply #8 on: November 13, 2006, 05:54:54 AM »

How many peaks are in the carbon NMR?  (Or proton, if you didn't get a carbon...)
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kiwi

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Re: Polycarbonyl reactions - caution difficult!
« Reply #9 on: April 28, 2007, 03:10:42 AM »

base-induced ring contractions of 1,2 diones aren't unknown, a similar reaction is used to prepare a SM of mine. at home so don't have the ref on me; look in scifinder for the reaction of cyclobutan-1,2-dione with sodium methoxide, it reacts in the exact same way.
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