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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: spritastic on March 16, 2011, 02:19:28 AM

Title: NMR Help (Aldol Condensation Rxn)
Post by: spritastic on March 16, 2011, 02:19:28 AM

Hey, I'm having trouble analyzing an NMR

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I just don't know how to go about analyzing Aldol NMR's

B/c of my MP, I've narrowed it down to:

1) Cinnamaldehyde + Acetone
2) 2-Furaldehyde + Cyclohexanone

Any help would be appreciated

Title: Re: NMR Help (Aldol Condensation Rxn)
Post by: sjb on March 16, 2011, 11:57:57 AM

Quote from: spritastic on March 16, 2011, 02:19:28 AM

Hey, I'm having trouble analyzing an NMR

(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fi54.tinypic.com%2Fqrdzq0.jpg&hash=7e51600684c342dbb9889bc2e3874654a6673108)

I just don't know how to go about analyzing Aldol NMR's

B/c of my MP, I've narrowed it down to:

1) Cinnamaldehyde + Acetone
2) 2-Furaldehyde + Cyclohexanone

Any help would be appreciated

Can you draw structures of your products from each of these? Based on this if you are sure one or the other of your choices is right then it may be a little clearer which is the correct answer.

Title: Re: NMR Help (Aldol Condensation Rxn)
Post by: spritastic on March 16, 2011, 12:12:30 PM

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Title: Re: NMR Help (Aldol Condensation Rxn)
Post by: sjb on March 16, 2011, 12:40:47 PM

OK, I was only drawing 1:1 adducts, but no problem. What characteristic shifts would you expect to see in, for instance the cyclohexanone?

Title: Re: NMR Help (Aldol Condensation Rxn)
Post by: spritastic on March 16, 2011, 12:47:31 PM

I don't know quite honestly...I suck at NMR's badly

Title: Re: NMR Help (Aldol Condensation Rxn)
Post by: mcdonabe on March 17, 2011, 02:47:32 PM

A) the first product will have a lot more protons in olefinic shifts (looking at the integrations)

B) Probably even easier, do you see any shifts for alkyl protons?