spirocycle
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eugenol -->vanillin
I know that with side chain oxidation, eugenol can be oxidized to the corresponding carboxylic acid, but would it be possible to limit this oxidation
to stop at the aldehyde?
I saw a mention of this in the vanillin thread, but there were no specifics.
I know I'm supposed to cite a reference here,
so:
http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/benz...
section 5 explains permanganate side chain oxidation
distillation wouldnt work, because eugenol is more volatile than vanillin.
possibly reacting it in a solvent that eugenol and the acid are soluble in, but vanillin isnt.
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Hexagon
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What? You've got to isomerize eugenol to isoeugenol and then oxidize the double bond to vanillin, that's how it was made in the old days, I think that
they used dichromate, search google pats. for a ref.
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entropy51
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There's already a thread on this, einstein. The search engine popped it right up.
Better to remain silent and appear a fool than to open your mouth and remove all doubt.
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Sobrero
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Recently I was reading in "Electrochemistry of Organic Compounds", Walther Löb, 1906 (available in the SMDB library), and it mentions on page 202 a
Deutsche Reich Patent DE92007 in which eugenol is electrolytically oxidized to vanilin. However, I'm unable to find the (1895) patent. Challenge
anyone? 
"There exists a world. In terms of probability, this borders on the impossible." (Jostein Gaarder)
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spirocycle
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Quote: Originally posted by Hexagon  | | What? You've got to isomerize eugenol to isoeugenol and then oxidize the double bond to vanillin, that's how it was made in the old days, I think that
they used dichromate, search google pats. for a ref. |
so the alkene reactivity takes priority over the aromatic side chain reactivity?
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mnick12
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Huh?
The reason why one isomerizes eugenol to isoeugenol is so that the double bond can be cleaved with the appropriate oxidizing agent into the aldehyde.
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Hexagon
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Yeah, the other way you would obtain homovanillin (the substituted phenyl acetaldehyde) and AFAIK if you would obtain vanillin would be through
overoxidation since the benzyl carbon is so prone to oxidation.
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postart
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Is phenylactaldehyde useful in benzedrin synth?
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spirocycle
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| Quote: Originally posted by mnick12 | Huh?
The reason why one isomerizes eugenol to isoeugenol is so that the double bond can be cleaved with the appropriate oxidizing agent into the aldehyde.
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i asked this because in chem class, we learned at aromatic alkyl groups are always cleaved to the methanoate.
So i was confirming that the alkene oxidation rules supercede the aromatic alkyl rules for oxidation
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