semiconductive
Hazard to Others
Posts: 325
Registered: 12-2-2017
Location: Scappoose Oregon, USA.
Member Is Offline
Mood: Explorative
|
|
de-aromatization and removal of ethene bonds.
I'm just curious. ( Beginner question. )
There are a lot of essential oils from 'green' sources that have an aromatic ring or at least several alkene bonds. These tend to be a bit more
reactive than I would like, although I'm interested in the ether and alcohol properties of some of them.
Is it possible to completely hydrogenate the aromatic ring so that it becomes a saturated hydrocarbon without opening the ring?
For example:
https://en.wikipedia.org/wiki/Eugenol
eg: If I took Eugenol, ( Purified clove oil ), and then tried to hydrogenate it, using palladium on carbon; would I be able to saturate all the
ethene bonds on the carbon ring, what about the tail ?
It this a difficult thing to do for an amateur?
Same idea with phenol, could it be totally hydrogenated, without destroying the -OH radical?
Or perhaps, vinyl or polyvinyl alcohols (no ring to worry about destroying.)
Thanks. 
|
|
|
Texium
|
Thread Moved
18-11-2022 at 06:41 |
Texium
Administrator
Posts: 4580
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
I suggest that you read the chapters on aromaticity and hydrogenation in literally any organic chemistry textbook. That will answer the bulk of your
questions.
|
|
|
Texium
|
Thread Opened
18-11-2022 at 08:00 |
Texium
Administrator
Posts: 4580
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
Not sure how this thread had gotten closed… I have re-opened it.
|
|
|
semiconductive
Hazard to Others
Posts: 325
Registered: 12-2-2017
Location: Scappoose Oregon, USA.
Member Is Offline
Mood: Explorative
|
|
Totally fair.
I am an Electrical Engineer, so I've only had inorganic chemistry.
I bought palladium on carbon from eBay, in hopes it's not a fraud.
The two ideas on the making potassium thread for improving the inertness of an alcohol, was Diels Alder reaction and Hydrogenation.
NurdRage on Youtube was originally going to show how to do full saturation of distilled tea-tree oil.
But, then he found that a secondary alcohol worked; namely Menthol. And it seems he lost interest in demonstrating the hydrogenation.
https://www.youtube.com/watch?v=iNbxgdBi4_I
But, I don't see hydrogenation of tea tree oil in his listings.
I repeated all the experimnets by forum drunkard on fractioning Turpentine, and ... well he didn't do anything wrong. The stuff is seriously
impossible to separate for an amateur. It's also frustratingly difficult to make into amber, or synthetic amber. Which is what I think he might have
done by accident when polymerizing it.
Let's see, the only book on organic chem, that I have is: Werthem And Jesky, Introductory Organic Chemistry (C)1956.
Diel's alder is not listed in the appendix, and palladium on carbon is not listed in the appendix.
Acetic anhydride is listed, and I was able to make that. Easy.
Grignard reagents is listed ... and I'm not sure I can do that, yet; but I suppose I could read that chapter.
So, hmmm.... hydrogenation, is that perhaps what I'm looking for?
Hydrogenation p443. Of oils, 164.
Turn to page, 443, and .... I see it.
| Quote: | | Hydrogenation: Addition of hydrogen (for example, to a double bond.) |
Hmm. Enllightening. Doesn't even mention if it's a resonant SP hybrid orbital, or not. I'm not sure if all alkene's are SP orbitals, though it
seems likely. Been, oh since 1990's since I used that information, could be wrong.
Turn to page 164, and I get a whole paragraph on it starting with:
| Quote: | 4. THe Hydrogenation of oils involves the addition of hydrogen atoms to the unsaturated linkages of glycerides. ... It is carried out by the use of
pure hydrogen, passed into oil, in the presence of powdered nickel, which acts as a catalyst.
After hydration, the oil is cooled then filtered to remove the catalyst. |
I have nickel-copper coins that I can file into dust to make a nickel-copper powder. Not sure that will work or not for hydrogenation; for that
matter; but if it's just a catalyst, then the reaction might be slower, but ought to still work.
I just hate wasting a lot of time on theories that should, but don't work.
And I always manage to find the exception to the chemistry rule, it's really quite .... maddening.
I've got a Buchner suction funnel with porous teflon filter paper.
And I read the rest of the paragraph, There's no information on temperature, pressure, or time, required to hydrogenate oils; just a note about
cotten seed oil product melting at 62C after Hydrogenation is complete.
I looked up araomatic rings on Wikipedia a while ago, and there was quite a bit of mixed information suggesting it was molecules that 'smelled'; which
when I asked about it (here), I got a bit ridiculed. It's hard being a beginner.
I look up aromatic rings, and Eucalyptol ... no information specific to anything like that. Tons of information on petrolium, kerosine fractioning,
you'd think the only thing they cared about was oil. Silly people.
I look up aromatic rings, and YES! Lots and LOTS of information. Too much information. There seems to be a hell of a lot of aromatic rings, from
napthalene's to vanilla oil, to you name it. It'll take me at least a month to memorize all this, and I don't think it will help. I tried melting
moth balls (Napthalene) in an Erlenmeyer flask, and that worked; but it proved near impossible to clean out, afterward. Ended up throwing away the
flask.
Any suggestions of what, precisely, I ought to look up?
It has a great index, it's just that none of the words I know get me to a chapter that has anything to do with what NurdRage was trying to do.
|
|
|
semiconductive
Hazard to Others
Posts: 325
Registered: 12-2-2017
Location: Scappoose Oregon, USA.
Member Is Offline
Mood: Explorative
|
|
Not alpha pinine to OL, I just managed to make synthetic amber. It's rock hard.
|
|
|
Texium
Administrator
Posts: 4580
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
Get a newer textbook. Preferably something from the 21st century. Or find one online. This is a good source: https://chem.libretexts.org/ You don’t have to memorize all the aromatic compounds in existence. There are quite simple rules for knowing if a
structure is aromatic or not (and no it has nothing to do with what it smells like). It seems like you’re poking at a lot of disparate things
without understanding the underlying ideas, so I suggest you read up more on the background rather than trying to cherry pick specific pieces of
information.
|
|
|
semiconductive
Hazard to Others
Posts: 325
Registered: 12-2-2017
Location: Scappoose Oregon, USA.
Member Is Offline
Mood: Explorative
|
|
Thank you for the link.
I'll continue to study it for a week more, before becoming annoyed. But it's strange that organic chemistry section table of contents doesn't
directly mention aromatics as a subject, anywhere; I just find it mentioned "in passing", like "Conjugate Elimination and addition in aromatics."
https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Supplemental_Modules_(Organic_Chemistry)/Reactions/Addition_Reactions/Addition_to_Carbonyls/
CO20._Conjugate_Addition-Elimination_in_Aromatics
Lot's of interesting tidbits of information there; I would, in fact, *LOVE* to learn all of that; but there's no explanations; just questions. Is
this a Socratic teaching text, where I need a teacher? Who's the teacher?
I figured out what an aromatic is, in spite of the condescention I experienced here when I believed stuff I found online at Wikipedia. I know a lot
of people argue over the Huckle Rule and edge cases.
FYI:
I got into a discussion of Buckminster fullerines, and their conductivity, and my predictions were correct.
(From the standpoint of quantum computing, not from the standpoint of making a buckminster fullerine, etc. which I don't know how to do. )
So, I'm not totally ignorant; just *mostly* ignorant.
I'm am ( as you suspect ) a total collection of eclectic organic chemical knowledge.
I know:
The Sigma + Pi double bond, and a resonance structure, typified by benzene is what's *mostly* meant by aromatic.
Hence, Eugenol and Vanillin, and are all pretty typical aromatics. right? (Or am I showing off my ignornace?)
I know that as the pi bonds get removed by hydrogenation, that the first reaction usually is easy; but subsequent reactions become increasingly more
difficult to force to happen.
SInce tea-tree oil is mostly not an aromatic, having only a single sigma pi bond; the last bond, I expect, will be the most difficult to remove.
So, give me a hint: Which chapters of the online source do I need to comprehend, before I can figure out the time, temperature, and pressure,
required to hydrogenate the double bonds ?
NurdRage already made it pretty clear in his video, that it is possible to do.
And I figure eugenol, would be a great experimental molecule to work with since it has a full resonant ring.
It easy to purify, in comparison to alpha-pinene,
and it's the kind of thing where I could test the difficulty of hydrogenating the ring from easiest, to hardest.
Of course, I could buy phenol, as a simpler example; but it wouldn't have the interesting side chains and the more complicated possibilites for
reactions; as mentioned on the conjugate addition/elimination page.
Besides, after all the trouble two *really* smart international hazards had in just trying to work with turpentine; I think I've done pretty well. I
am in full agreement, that several online articles and patents about how *easy* it is to work with, are lies! lies! lies!
Most reactions end up with side reactions *all* over the place, and very few are easy to separate.
Which is why I thought I'd ask about a specific molecule, eugenol, or terpin-4-ol (from tea-tree).
Again, I'll happily read the text for a week.
I hope you aren't hazing me by sending me to look for a left-handed-screwdriver, when there isn't one. 
Cheers.
|
|
|
clearly_not_atara
International Hazard
Posts: 2787
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
Generally de-aromatization reductions are most feasibly achieved with the Birch-type systems. Birch reductions of phenols are reported to produce
cyclohexenone derivatives with good stoichiometry control, though this can probably be reduced further as it is quite reactive.
|
|
|
j_sum1
Administrator
Posts: 6320
Registered: 4-10-2014
Location: At home
Member Is Offline
Mood: Most of the ducks are in a row
|
|
If it was me, I would begin with phenol.
|
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
