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idontlie
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Aldol Condensation of Piperonal with Acetone
Essentially this document is why the DEA isn't worried about aldol condensation of piperonal. Maybe they are but are killing off those who discover
the secret. What do you think?
The reactive portion on piperonal, the aldehyde, in an Aldol condensation can be thought of as Benzaldehyde. We must be wary of damaging the
Methylenedioxy group and being forced to clean up the product. Either by throwing away the incorrect product which would kill the yield. Alternatively
you could follow the eugenol/vanillin Demethylation and Methylenation procedures discussed in detail, elsewhere, to hope to fix your little mess.
Which would remove the benefit of spending the effort to extract piperine, and following the path through piperic acid then to piperonal via copper
oxides [1] which is in and of it self a piece of work, rather than starting with eugenol or pyrocat.
Primary Reaction:
Benzaldehyde + Acetone in NaOH, Water, and EtOH yielding Benzalacetone. [2] Suggests shaking our Benzaldehyde (piperonal) with soda ash (PH Plus at
pool stores) then distilling to get fresh, clean and happy product.
Take special note of note 8 of [2]. This is a anisaldehyde (similar to vanillin) + acetone of the same procedure yielding anisalacetone at 83%. So our
condensation should give around 80% yields from piperonal.
Side Reaction:
Benzaldehyde + Acetone in NaOH, Water, and EtOH solution yields Dibenzylideneacetone. [3][4] Just look at that sucker. It would be much better to
avoid this product all together than to attempt to convert it. We can avoid this by excess acetone. Acetone is 4$/L, How much is your piperonal worth?
At this point we have 3,4-methylenedioxy-Benzalacetone, CAS 3160-37-0. This is not MDP2P our chain is one carbon to long on the MD-Benzene side of
the ketone. Additionally we have a double bond between 1 and 2 carbons in our chain. So the route for methyl phenyl butanone to P2P discussed in the
hive wont do anything useful for us.
So where can we go from here? Can't it be oxidized with peracetic acid to to MDP2P?
It makes an isosafrole ether
"In this connection it is of interest that Boeseken and Kremefl recently
have observed that benzalacetone, in a closely analogous manner, is transformed
by means of peracetic acid into styryl acetate
C6H5CH=CHCOCH3 -> C6H5CH=CHOCOCH3" [5]
The DEA's fine scientists laugh at these feeble attempts to create mdma from pepper without the fun of nitroethane. Can they be proved wrong?
[B]References[/B]
[1] Pepper no 5 http://www.zshare.net/download/6302381912893464/
[2]http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV1P0077
Dibenzylideneacetone Aldol Condensation:
[3]http://www.scribd.com/Aldol-Reaction/d/493707
[4]http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv2p0167
[5] THE REACTION BETWEEN KETOXIDO COMPOUNDS AND GRIGNARD REAGENTS
Ernst Bergmann, H. A. Wolff
J. Am. Chem. Soc., 1932, 54 (4), pp 1644–1647
[Edited on 3-1-2010 by idontlie]
[Edited on 3-1-2010 by idontlie]
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turd
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Nice post!
But this seems to be quite useless if the goal is one of the essential amphetamines. First of all "iso-safrole acetate" (I think there's a C missing
in the picture!) is not and will not hydrolize to iso-safrole. And even if one could remove that OH-group, one is still at least 2-3 steps away from
the final amine.
Let's say 6 steps in total with 50% yield per step makes 0.5^6 ~ 1.5% of total yield. For 15g of final product one would have to start with 1kg of
piperonal. This is not counting initial optimization experiments. Now imagine what kind of solvent volumes and equipment are needed at that scale!
And contrast that to the simple well known two step condensation + reduction reaction... I think making nitroethane, even if troublesome, would be
easier...
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Arrhenius
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The Baeyer-Villiger oxidation of the enone is going to be problematic. This is a nucleophilic reaction, and enones are not particularly reactive
towards 1,2-addition. You're adding three carbons in the aldol condensation, and then wanting to remove two. Why not use nitromethane?
Nitromethane is commonly employed in the Henry reaction as a "one carbon building block". Hydrogenation or hydride reducation of the double bond,
followed by the Nef reaction would give the phenylacetaldehyde much more effectively.
You'll find your time better spend scheming up ways to make exactly what you want, not scheming up reactions to do with a given substrate.
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idontlie
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Thank you!
Quote: Originally posted by turd | But this seems to be quite useless if the goal is one of the essential amphetamines. First of all "iso-safrole acetate" (I think there's a C missing
in the picture!) is not and will not hydrolize to iso-safrole. And even if one could remove that OH-group, one is still at least 2-3 steps away from
the final amine. |
I wouldn't be surprised that I'm missing a carbon. I just had the computer generate styryl acetate and added the methylenedioxy group. This was a last
minute addition from another conversation that peracetic acid was suggested as a direct mdp2p which was found to not be the case. Just had it there
for "posterity." This is simply writing on the fly to track thoughts and to share the thoughts.
Quote: Originally posted by turd |
Let's say 6 steps in total with 50% yield per step makes 0.5^6 ~ 1.5% of total yield. For 15g of final product one would have to start with 1kg of
piperonal. This is not counting initial optimization experiments. Now imagine what kind of solvent volumes and equipment are needed at that scale!
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hehe. Yeah not economical but "novel." Even though this is "novel," I was hoping for the off chance of 80% yields from the reaction chain. With an
overall yield of ~25%. The aldol condensation itself should be around 80% (see note 8 of [4]) After the condensation, I haven't seen anything worth
following or even know where to look.
Quote: Originally posted by turd |
And contrast that to the simple well known two step condensation + reduction reaction... I think making nitroethane, even if troublesome, would be
easier... |
You're probably right. I'm in no way saying this is a good idea to try on a production scale but rather to say, "Ok, we all hear about aldol
condensation being thrown around as the big beast. Does it actually work to reach a goals and if so how?"
Quote: Originally posted by Arrhenius | The Baeyer-Villiger oxidation of the enone is going to be problematic. This is a nucleophilic reaction, and enones are not particularly reactive
towards 1,2-addition. You're adding three carbons in the aldol condensation, and then wanting to remove two. Why not use nitromethane?
Nitromethane is commonly employed in the Henry reaction as a "one carbon building block". Hydrogenation or hydride reducation of the double bond,
followed by the Nef reaction would give the phenylacetaldehyde much more effectively.
You'll find your time better spend scheming up ways to make exactly what you want, not scheming up reactions to do with a given substrate.
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Thank you, I have some reading to do.
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mr.crow
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Well it is rather fun thinking of synthetic routes, even dubious ones...
What would be better would be hydrogenate the double bond and make something like Raspberry Ketone. I bet the piperonal derivative would smell really
nice!
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entropy51
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Quote: Originally posted by idontlie | Essentially this document is why the DEA isn't worried about aldol condensation of piperonal. Maybe they are but are killing off those who discover
the secret. What do you think? | I think you needn't lose sleep about the prospect of DEA putting out a
contract for a hit on you.
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idontlie
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Quote: Originally posted by mr.crow | Well it is rather fun thinking of synthetic routes, even dubious ones...
What would be better would be hydrogenate the double bond and make something like Raspberry Ketone. I bet the piperonal derivative would smell really
nice! |
I looked at the paper for raspberry ketone its missing that double bond found in our condensation product cute little tail. Not sure on the why as its
created using crossed aldol. Perhaps I don't understand all of aldol, which is likely the case.
EDIT:
Turns out I do understand aldol condensation. The Benzalacetone like produce will always have that double bond. It is stripped by "Selective
atmospheric hydrogenation over Pd/C." [6]
I know but its much more fun to think this way. =)
References:
[6] http://www.homechemistry.org/index.php?title=Preparation_of_Zingerone_(Ginger_aroma)_from_vanillin#Second_step:_Selective_atmospheric_hydrogenation_ov
er_Pd.2FC
[Edited on 4-1-2010 by idontlie]
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mr.crow
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So its the aldol reaction, then hydrogenation
You should read the PDF in this thread, very well done http://www.sciencemadness.org/talk/viewthread.php?tid=12780
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idontlie
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Haha, Thank you. I just saw that from another source. =) Check my edit above.
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Bolt
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The condensation with methyl ethyl ketone followed by the Baeyer-Villager oxidation is more along the lines of what you're wanting, I think.
http://www.sciencemadness.org/talk/viewthread.php?tid=6449
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idontlie
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Quote: Originally posted by Arrhenius | The Baeyer-Villiger oxidation of the enone is going to be problematic. This is a nucleophilic reaction, and enones are not particularly reactive
towards 1,2-addition. You're adding three carbons in the aldol condensation, and then wanting to remove two. Why not use nitromethane?
Nitromethane is commonly employed in the Henry reaction as a "one carbon building block". Hydrogenation or hydride reducation of the double bond,
followed by the Nef reaction would give the phenylacetaldehyde much more effectively.
You'll find your time better spend scheming up ways to make exactly what you want, not scheming up reactions to do with a given substrate.
|
Back here... The nitromethane addition is documented at rhodium under "3,4-Methylenedioxyphenyl-2-Nitropropene From Piperonal, Nitroethane & NaOH"
see 2,5-Dimethoxynitrostyrene from 2,5-Dimethoxy benzaldehyde. [7]
The nitromethane addition is documented in detail. [8]
Is there anything worth looking at in the "magic" section for our nitroalkane.
edit:
Im not sure about this but the, suggested, nef reaction yields this?
References:
[7] MDP2NP Rhodium
[8] http://www.organic-chemistry.org/namedreactions/henry-reaction.shtm
[Edited on 4-1-2010 by idontlie]
[Edited on 4-1-2010 by idontlie]
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Nicodem
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Quote: Originally posted by idontlie | Essentially this document is why the DEA isn't worried about aldol condensation of piperonal. Maybe they are but are killing off those who discover
the secret. What do you think? |
I think that self deluding into believing such things is highly infantile. If you think you need to be kewlish to be interested in chemistry you are
quite wrong. Chemistry can be interesting even if you drop the kewlish attitude and take it seriously and maturely. It might look hard and confusing
at the beginning and this may put you off, so it may be fine for you to believe that fantasizing about opposing the authorities by pretending criminal
intent is helping you to get over the initial learning phase. Yet do us a favour and spare your dirty little fantasies to yourself and stick only to
science in your public posts. That's just what I think about it.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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idontlie
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Thank you.
I don't want to be cool or even attempt these reactions. I have no intention of breaking the law or ever even having piperonal much less using it to
make something else illegal. This is meant to be a discourse on the avoidance of nitroethane. I just was curious about these thing called aldol
condensation after it was mentioned in passing conversation as the "Dark Secret."
I figured if it was actually useful it would have been documented and as there was a lack of documentation; I wanted to share why aldol is in fact not
used, at least in the way mentioned. Furthermore, I figured it would be novel to display an alternate route.
If someone actually wanted to produce an illegal substance they would be more than willing to take the risks and go through the effort to make
nitroethane and get exactly what they want. Hell they probably wouldn't even want to experiment with their "product" in fear of ruining their cooking.
But thank you for dismissing my curiosity as infantile. You truly inspire the masses.
__________________
edit:
I am curious about the nef reaction on the nitromethane product of piperonal. The product does not look right to me, especially not the carbon being
double bonded to both another carbon and the nitrogen but as I am only an infant and don't know better... Wouldn't this be an unstable product prone
to decomposition?
Will the product have to be hydrogenation to strip the double bond, becoming saturated, then used in the nef reaction?
[Edited on 4-1-2010 by idontlie]
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Nicodem
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Quote: Originally posted by idontlie | This is meant to be a discourse on the avoidance of nitroethane. I just was curious about these thing called aldol condensation after it was mentioned
in passing conversation as the "Dark Secret." |
Maybe you watch too much television, because I don't think there is any such thing as a "Dark Secret" in chemistry.
There is a thread on the forum about acid catalysed aldol condensation of methyl ethyl ketone with benzaldehyde followed by a Baeyer-Villiger
oxidation to yield 1-phenylpropen-2-yl acetate. It is most likely you got your idea from there via somebody who did not fully understood the synthetic
route.
Quote: | But thank you for dismissing my curiosity as infantile. |
My pleasure.
Quote: | I am curious about the nef reaction on the nitromethane product of piperonal. The product does not look right to me, especially not the carbon being
double bonded to both another carbon and the nitrogen but as I am only an infant and don't know better... Wouldn't this be an unstable product prone
to decomposition? |
The product you depicted is from a class of compounds called ketenes (R2C=C=O). These are highly electrophilic and react relatively rapidly with any
nucleophiles (including water). In this respect they are analogous to acid chlorides, not just due to the reactivity, but also because in their polar
reactions they give the same products as the corresponding acid chlorides (R2CHCOCl). They are also very reactive in many pericyclic reactions, even
so much that unless the substituents (R) are bulky enough they slowly react with themselves forming four membered rings. But this is not important
because you can not prepare ketenes via the Nef reaction. If you check the mechanism of the Nef reaction you will see that it is actually a hydrolysis
of the nitronate salt. To obtain a nitronate you need a nitroalkane (and not a nitroalkene as in your case). The beta-nitrostyrenes can form a
nitronate with hydroxides but only after the 1,4-conjugate addition of a hydroxide. Such a nitronate, even if it could be hydrolysed, would give
2-hydroxy-2-phenylacetaldehyde (or its rearrangement/decomposition products, due to the instability in acidic media required for the hydrolysis).
The simplest 1C synthon you can attach on a beta-nitrostyrene is formaldehyde via the Baylis-Hillman reaction. For example, as described in
Tetrahedron Letters, 45 (2004) 4745-4748.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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turd
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It's quite strange that, given that you start with a 1C chain and want to end with a 3C chain, you first tried an addition of 3 Cs and then 1 C, when
the obvious choice would of course have been to add 2 Cs. Maybe a Grignard with
EtMgBr? No idea if that would work (I faintly remember cooking a Grignard eons ago where the substituent then ended up on the ring instead of on the
side-chain!), but the resulting alcohol sure looks like it would easily dehydrate to iso-safrole.
There's a standard text on organic synthesis: "S. Warren, Organic Synthesis: The Disconnection Approach". Maybe this can help you better organize your
synthesis plans. As in concentrate on the product, and do not start with random synthesis steps. For me this will always be black magic, I'm glad when
I can make my few favorite target molecules...
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idontlie
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Thank you.
The only source that I've found for a somewhat similar grignard reaction has reported yields of 18%. And by somewhat I mean just about not at all. Are
there catalysts that exist to increase this yield?
Especially considering piperonal from piperine is a rather lossy. Not to even mention the 3 to 5% yield of piperine from raw pepper and thats using a
microwave extraction, which is supposedly better. Then two ~70% reactions the first being the wonderful little degradation to piperic acid. The second
being piperic acids cleavage using hydrated copper sulfate and lye.
Also, these reactions seem to be only documented in ether and ether is scary. I read a document by weylchem that claims that solvents as common as
toluene. [1] Toluene is nice, cheap and legal.
Anyways, I'll be sure to check out the book.
[1] http://www.weylchem.com/fileadmin/Downloads/WEYL_GrignardReagents.pdf
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turd
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Organikum states 78% for benzaldehyde + EtMgBr --> 1-phenyl-propan-1-ol and usually these old socialists know what they are doing. How will the methylenedioxy group interfere? Well, don't ask me!
Grignard reactions can be done in a home-chemistry setting, been there, done that, great yields. I think with an endeavor like that the ether is the
least of your troubles...
BTW: Check out if there is a chemistry library in your vicinity with SciFinder and/or Beilstein/Crossfire access. There you will find many (but not
all) published reactions.
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JohnWW
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That reminds me: it is about time that someone, with appropriate access, downloaded the whole of SciFinder and Beilstein Crossfire, and re-uploaded
them to either Madhatter's FTP or to a file-hosting site (such as rapidshare.com) that can accept appropriately large files.
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entropy51
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Benzaldehyde + MeMgBr -> phenylmethyl carbinol
90% when run in toluene. Grignard was made in ether, of course.
The benzaldehyde was substituted, but NOT methylenedioxy.
If ether scares you, please don't try to make methylenedioxy whatever. Prison is much more
scary than ether.
[Edited on 5-1-2010 by entropy51]
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idontlie
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@entropy51:
I have a healthy fear of all things other than plain white bread. I have no intention of doing any of these reactions or even having the means to do
so; I simply enjoy talking and learning. I was a danger to myself and others in high school chem. lab and decided that was the end of physical
experimentation. Talking won't get you thrown in the bing.
@turd:
I believe the library does in fact have SciFinder access but the remote access I've been using is problematic at best. (the library shares its
accounts with other libraries and decides you've been inactive immediately). I'll have to try using it when at the library, next.
Thank you for the suggestion, once again.
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Klute
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You seem pretty confused as of what can be obtained from the enol ester.. The oxygene isn't going to chup off like that and leave an alkene..
If one wanted to form a phenylpropylamine, one would better do the acidic aldol with mek followed by a Bayer Villiger oxidation with your favourite
peracid, followed by hydrolysis, although the aldol with piperonal is rather low yielding compared to benzaldehydeIIRC (some japanese ref somewhere).
If I had some piperonal, I would do the aldol with acetone just like you suggested, then hydrogenated it as per my write up you referenced! You would
obtain the aroma of blackcurrant! It must smell extremly nice!
That would be the best use of piperonal according to me
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
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idontlie
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Quote: Originally posted by Klute |
If one wanted to form a phenylpropylamine, one would better do the acidic aldol with mek followed by a Bayer Villiger oxidation with your favourite
peracid, followed by hydrolysis...
|
First, thank you for that write up. You might want to check step one your vanillin is wrong. You have some ketone rather than the aldehyde you want to
be displaying. Not that it really matters.
Second, like I said I am not in any way a chemistry buff. I just enjoy learning new things. But I have a problem with your procedure. You are saying
3,4-methylenedioxy-Benzalacetone obtained after the condensation is going to go through Baeyer-Villiger Oxidation to form my isosafrole Ester and ill
be able to do what to get a phenylpropylamine?
From what I understand I'm going to end up with a acetone salt and an alcohol. That alcohol is rather problematic isn't it? Wouldn't I end up with a
aldehyde at best?
I was looking at
http://www.organic-chemistry.org/namedreactions/baeyer-villi...
If you could show some sources that would be amazing. Thank you.
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Nicodem
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I already told that this was already discussed here. All you needed to do is UTFSE:
http://www.sciencemadness.org/talk/viewthread.php?tid=6449
http://www.sciencemadness.org/talk/viewthread.php?tid=6880
http://www.sciencemadness.org/talk/viewthread.php?tid=9814
There might be other threads on topic, but I leave you to practice on how to UTFSE yourself.
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Klute
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No, no, I was talking of the aldol product with MEK, catalyzed by HCl gas.. That would get you to the propanone, but with low yields..
ANd you would not obtain a alcohol from your enol ester, as it is a ENOL ester, as soon as it would be hydrolyzed (giving acetic acid), it will
tautomerize to the phenylacetaldehyde..
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
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Sedit
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People have discussed in the past the acid catalysed Aldol condensation of MEK and piperonal but to me this appears completely unreasonable. The
methylenedioxy ether is very sensitive to acid cleavage as I understand it so how on earth could it possibly withstand the abuse of hours on end of
HCl gas being pumped into the solution without leaving you with nothing more then polymerized goop?
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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