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Author: Subject: Acetone + NaOH --> ?
hodges
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[*] posted on 28-10-2004 at 14:18
Acetone + NaOH --> ?


I read that acetone is not stable under basic conditions. What would the product be if a strong base, such as NaOH, was added to acetone? For that matter, what if Na was added to the acetone?
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The_Davster
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[*] posted on 28-10-2004 at 14:55


You beat me to this question hodges:P.
I was about to ask something similar. In the CRC or Merck(forgot which) it states that acetone + base + chloroform is an explosion hazard, however I have used this reaction a handfull of times to make chlorobutanol. Why exactly is there an explosion hazard here?




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[*] posted on 28-10-2004 at 15:19


acetone can polymerize under basic conditions.

the danger with chloroform is that you can form a dichlorocarbene (through net loss of HCl) which is very reactive.
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[*] posted on 28-10-2004 at 16:41


According to my lovely org. chem book,
acetone reacts in alkaline conditions to diacetone alcohol, i.e. (CH3)2COH-CH2CO-CH3
Under acidic conditions (H2SO4) one gets mesitylen (1,3,5 trimethyl benzene), at least under certain conditions ( I think there's been a thread on it)

By the way, diacetone alcohol is, with a trace of acid or idone, dehydrogenated to mesityloxide, (H3C)2C=CH-CO-CH3.

According to that book, phorone is made by bubbling HCl gas through acetone, whereby a side product is mesityloxide. But maybe that belongs to another thread. Phorone btw is a yellow compound melting at 28 deg C.

Although somewhat off topic, this has always been an area of fascination to me - to generate the benzene ring from something as simple as acetone. Here's the production of mesitylene....
http://www.worldwideschool.org/library/books/sci/chemistry/O... - oh, and by the way, have a look at the other links in that site - they are very intersting...

[Edited on 29-10-2004 by chemoleo]




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[*] posted on 29-10-2004 at 22:28


Doesnt acetone undergo an aldol condensation under basic conditions? Does it have a different name when it happens to a ketone?

In any case, it does form the beta-hydroxyketone that chemoleo mentioned. Happens to any aldehyde or ketone with alpha-hydrogens - the base removes one of these hydrogens (made much more acidic than normal hydrogens due to the adjacent carboyl group). The generated carbanion attacks the carbonyl of another ketone, which results in a b-hydroxyketone. Nice reaction, really!! :)

On the off topic comment, it's prety easy to make mesitylene via that method... if you wanted benzene, perhaps it would be possible to oxidise the methyl groups to benzoic acids and then decarboxylating the molecule (KMnO4 followed by standard decarboxylation, possibly having to be done in up to three times to get each methyl)? Just a thought... If i recall, mesitylene is on my "avoid this unless you have a fume hood" list, on grounds of smell...
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