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Assured Fish
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[*] posted on 28-9-2018 at 16:51



Quote:

Tosylation of the alcohol followed by treatment with LDA to give the target compound via an intramolecular alkylation.

I knew it!
Im not crazy, there is a way to do that. Mwahahahahaha
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j_sum1
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[*] posted on 28-9-2018 at 18:32


I made it! I made it!!

Yield is a bit bleak though. I only got one molecule.

2018-09-29 12.06.05.jpg - 59kB
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[*] posted on 28-9-2018 at 18:41


On a more serious note...
Some things that may or may not have been noticed by those working on this problem.

1. There are two chiral centres and so two diastereomers. (Labelled in the following photos by the purple bonds.)
2018-09-29 12.07.01.jpg - 59kB 2018-09-29 12.07.54.jpg - 61kB

2. There seems to be a lot of bond strain. At least if the model kit is anything of an indicator. The structure really wants to fly apart. The trans isomer in particular. I am not predicting that the synthesis will be easy at all.



[Edited on 29-9-2018 by j_sum1]
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[*] posted on 28-9-2018 at 18:54


Throwing it into my phone app...

2018-09-29 12.43.41.png - 84kB 2018-09-29 12.45.21.png - 192kB
2018-09-29 12.47.01.png - 87kB 2018-09-29 12.48.20.png - 222kB

(Webmo if anyone is interested.)
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CuReUS
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[*] posted on 29-9-2018 at 08:46


Quote: Originally posted by Assured Fish  
is it possible for an alcohol to react in an aldol condensation with an enol instead of classically reacting an aldehyde with an enol?
I think this was the reaction you were hoping to find and are so ecstatic about now.But this is merely the alkylation of enolates using an activated alcohol(tosylate in this case) as the electrophile.You can't call this an aldol condensation.
Quote: Originally posted by j_sum1  
1. There are two chiral centres and so two diastereomers.
actually,there are 5 chiral centres.But since jackson wants to use this molecule as a base for bucky balls,I don't think stereochemistry would matter much.As long as it doesn't have to fit in a particular receptor(like drugs),it should be fine.I may be wrong though :D

Also,the synthesis is already very hard as it is.Trying to make it asymmetric would be next to impossible.

I suggest we try getting a product first as proof of concept.This could be done by selecting the 2 best routes posted,correcting their flaws and optimising them( like figuring out how many steps could be run in one pot).Then jackson could do a trial run and report back here.

[Edited on 29-9-2018 by CuReUS]
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[*] posted on 29-9-2018 at 15:04


Quote:
actually,there are 5 chiral centres.

Then either I can't count or I have some confusion over what a chiral centre is. I am happy to be educated.

My point is that playing with the model kit I get two isomers: one concave and the other somewhat twisted. Both structures are quite strained to the point that the kit pops open. (I know this is no substitute for good theory and supporting calculations. But modelling does help with getting a feel for things.)

[Edited on 29-9-2018 by j_sum1]
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CuReUS
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[*] posted on 30-9-2018 at 10:51


While trying to come up with the route I suggested in the previous page,I faced a dilemma about which protecting group to use.I was torn between converting the primary alcohol and enol to an ester(benzoate) or ether(methyl ether).In the end,I chose benzoate since it was less toxic and the deprotection was a breeze.

But that time I had a nagging doubt - would the Mg used for the pinacol coupling react with the ester ?

I went through greene's book on protective groups,and I am sorry to say, my fellow chemists,but my doubts have been confirmed :( - https://www.sciencedirect.com/science/article/pii/S004040390...
https://www.sciencedirect.com/science/article/pii/0040403995... (don't know why they published the same thing again after 2 years using different authors)

Although the deprotection condition is Mg/MeOH,rt for 13 h,I don't want to take any chances :D

So I suggest we proceed via the ether route.The reaction stays the same,the only difference is that the starting material is different ( CAS no: 4683-50-5) and we do a methylation step instead of benzoylation.

the methylation could be done with dimethyl sulphate/Barium hydroxide-https://pubs.acs.org/doi/10.1021/jo00374a020

or methyl iodide/silver oxide-https://pubs.acs.org/doi/10.1021/ja00545a041

deprotection can be done by trimethyl silyl iodide -https://pubs.acs.org/doi/10.1021/jo00443a033

or BBr3-https://www.jstage.jst.go.jp/article/bbb1961/42/1/42_1_131/_...
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Assured Fish
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[*] posted on 30-9-2018 at 20:48


Ive been researching how one could go about preparing the starting material 3-hydroxy-2-cyclopentenone or an ether thereof.
I found the following paper, which looks promising although entails 3 steps.
https://cdn-pubs.acs.org/doi/10.1021/jo010593b
Sadly ive yet to get access to see what its limitations are or the exact conditions used but it would mean starting from commercially available acrylic acid acid or an ester of acrylic acid, acetylene, HBr and a ruthenium catalyst of some kind, i suspect the solvent would be THF.


Not sure which is looking more promising at the moment, the naphthalene route or the cyclopentenone route but the later is certainly more developed.
Although some of the reagents are a tad exotic.

[Edited on 1-10-2018 by Assured Fish]
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[*] posted on 1-10-2018 at 05:04


Quote: Originally posted by Assured Fish  
Ive been researching how one could go about preparing the starting material 3-hydroxy-2-cyclopentenone or an ether thereof.
There is no need to make it,since jackson can directly buy it. :)
Quote:
Although some of the reagents are a tad exotic.
They might be "exotic" from a home chemist's point of view,but they are quite commom in an university setting,where jackson is working. ;)

[Edited on 1-10-2018 by CuReUS]
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[*] posted on 1-10-2018 at 07:08


Just to clear things up im not working at a univeristy currently so these reageants are going to be difficult to get access to. I know people that work at a university that can help me get access to analytical equipment. I do know someone that could potentially help me get access to chemical suppliers .
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[*] posted on 1-10-2018 at 12:53


You will probably enjoy this paper:
https://sci-hub.tw/10.1002/anie.200705775
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[*] posted on 1-10-2018 at 22:07


Quote: Originally posted by Jackson  
Just to clear things up im not working at a univeristy
the reason I said "working" was because I thought you are a student who has access to an university lab and reagents since you said you wanted to make bucky balls,and another member had also worked with them when he was in school.(zts16 I think)
Quote:
I do know someone that could potentially help me get access to chemical suppliers .
You could also buy them online cheaply,from chinese suppliers.See the "Reagents and apparatus acquisition" sub forum for more info.
Quote: Originally posted by TGSpecialist1  
You will probably enjoy this paper
what's your point ?
strained compounds exist.That doesn't mean they can't be synthesised -https://en.wikipedia.org/wiki/Bicyclobutane
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[*] posted on 2-10-2018 at 10:31


Im an Idiot.
I forgot to ask a very important question.
This molecule is a segment of a larger molecule. I forgot to ask if the larger molecule could even be made from this molecule.
I will attach a photo of a model of the full molecule.

P.S. the red bonds are single bonds, white bonds are double bonds. The open double bonds on the end are supposed to be where the oxygen it bonded.

F31C6839-16F8-4AAD-9EB1-159E2C6C4E25.jpeg - 1MB
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[*] posted on 3-10-2018 at 11:33


The precursor molecule could be made by the gringard reaction of
4-amino-2-bromomagnesium-but-1-ene and 3-amino-acrolein. Then this could be cyclized by a lewis acid.
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Assured Fish
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[*] posted on 3-10-2018 at 13:11


Holly jebus.
I dont have the time to answer your question in full but primary and secondary amines are incompatible with grignard reagents as the organo magnesium halide carbon will just deprotonate the amine.
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[*] posted on 3-10-2018 at 13:17


Could the amines be converted into a different group?
If so, would something like a nitrate group be fine?
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[*] posted on 3-10-2018 at 21:33



Quote:

Could the amines be converted into a different group? If so, would something like a nitrate group be fine?


I think you mean a nitrite group, organo nitrates are very unstable and dangerous to prepare e.g. nitroglycerin.
The answer is no, you need to do some research on the exact mechanism of a grignard reaction so you can understand its limitations.
Another group is possible yes but your route is flawed i have a better one but will need to do some work on it which will take a few days (im very busy at the moment).

Now, as for your fullerene material, I need to crush your expectations.
You cannot make that compound starting from the pyracenedione species we have been working on in this thread.

A method for making such a compound is probably well beyond what the members on this site are capable of, even if we were to come up with a theoretical route, the route would likely involve so many steps that the sheer difficulty in preparing the compound would make it synthetically useless.

It certainly looks like it might have some uses to the species but these kind of projects are the kinda things large research labs spend tens of millions of dollars on and several decades to develop, usually in the hopes of earning some Nobel prize or something.
The major issue with preparing it is trying to prepare a large 16 carbon substituted cyclocarbon species, which would likely be the backbone for the material.

Im sure i could find some approach to preparing such a molecule (with many flaws) but you will likely never be able to make it.
Im sceptical of you being able to prepare the hexahydo pyracenedione molecule as is.

Buckyballs or buckminsterfullerene is not prepared using methods commonly used in organic chemistry (that would be insane), it is by some miracle prepared by simply passing an arc between two graphite electrodes at a very high voltage and then isolated using an organic solvent as the fullerene is soluble whereas carbon is not.
This kinda information is available from the video periodic videos did on the substance.
https://www.youtube.com/watch?v=ljF5QhD5hnI

If you want to prepare it then by all means, it would be an interesting project and this paper may be of some use to you.
Beyond that though, i can do some research about preparing that thing of yours, i will make no promises, i will almost certainly fail and if i come up with something it will be a mess.


Attachment: zhu1993.pdf (317kB)
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[*] posted on 4-10-2018 at 08:02


I actualy found a paper that created C60 using a chemical process.

I will send a link to this thread if I can find it.

My analogy to a buckball for my final molecule was not a very good one as the final molecule I wanted to make is not a fullerene. This was more of a theoretical idea than something I was going to practically pursue. I will probably attempt synthesis of the pyracenedione once I get some more materials and equipment needed for it.
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[*] posted on 4-10-2018 at 08:09


http://science.sciencemag.org/content/295/5559/1500.full

Here is the link to the article.
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[*] posted on 4-10-2018 at 18:21


I sure can't see 5 chiral centers in that molecule either.

Is there some stuff about heterocyclic structures or something I'm forgetting here?




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Assured Fish
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[*] posted on 5-10-2018 at 18:29


I also do not see five chiral centres, havent a clue why Atara stated that, perhaps an oversight on his part.

Anyway, this is route for the preparation of the cyclopentenone species.

cyclopentanone species working synth.png - 10kB

Based on the research done in the paper trost2001.

for each of the 3 steps they worked up by way of ethyl ether/petroleum ether over silica gel by way of chromatography.
The last step needs to be done quickly as the geminal diol ether compound is likely unstable, it is also moisture sensitive and chromium 2 chloride is hydroscopic.

This is the ruthenium catalyst used in the first step.
https://www.sigmaaldrich.com/catalog/product/aldrich/667412?...

Yields would likely vary too much to be of much importance but for each step they reported above 60% and the 3rd above 80%.
It would be better if you read the paper yourself.

That first step is somewhat problematic as acetylene is probably not highly soluble in acetone at the reflux temp required for the reaction, a continuous flow of acetylene would likely be required, which would sap energy away from the reaction so a strong heat source would be a necessity.
Thankfully an excess of acetylene would not hinder the reaction or take place in side reactions.

Unfortunately there is nothing easy about this kinda synthesis, non of the materials with exception of the solvents are easily accessible.
Honestly the more i read into it the more i start to learn towards Atara's route starting from naphthalene.

All of this stuff is just madness, well beyond what i would be willing to do, especially with no obvious use for the end product.
A hell of a lot of money would be required to buy reagents, or time required to prepare the more easily prepped ones like PDC and nickel dichloride.
Stannic bromide would be horribly difficult to prepare, buying it would be necessary which would also be challenging.

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[*] posted on 6-10-2018 at 07:23


Quote: Originally posted by Assured Fish  
I also do not see five chiral centres, havent a clue why Atara stated that, perhaps an oversight on his part.
atara didn't state that,I did :P
And I was wrong,its 2 only :D
Quote:
Unfortunately there is nothing easy about this kinda synthesis, non of the materials with exception of the solvents are easily accessible.
that's because you have yourself complicated it.:mad:
I said so many times that the starting compound is directly available commercially.

Still, you insist on synthesising it,that too via a ridiculously convoluted route,when it can be made in 1 step from 1,3-cyclopentanedione(another commercially available product) -https://pubs.acs.org/doi/10.1021/jo801911s(pg 9 of pdf,compound 74) , which in turn can be made from methyl/ethyl levulinate -https://patents.google.com/patent/US7897802B2/en

ethyl levulinate is available as biofuel - https://en.wikipedia.org/wiki/Ethyl_levulinate, or if you truly wanted to make it from scratch,you could make it from sugar -https://en.wikipedia.org/wiki/Levulinic_acid#Synthesis

Quote:
Honestly the more i read into it the more i start to learn towards Atara's route starting from naphthalene.
But the birch reduction step is doubtful,and there is no ref to back it up.
the only reason I suggested the cyclopentanone route was because I couldn't find a ref for the reduction of PCD,which I still think is the easiest way to make this molecule.
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[*] posted on 20-10-2018 at 19:43


Another idea for a route could be:

Synthesis of 1,5 dimethyl napthalene as shown here: https://wikivisually.com/wiki/2%2C6-Dimethylnaphthalene (without the final step)

Then bromination of both of the methyl groups to form 1,5 dibromomethyl napthalene

Then reacting the 1,5 dibromomethyl napthalene with sodium cyanide to form 1,5 diacetonitrile napthalene

Then hydrolysis of 1,5 diacetonitrile napthalene to form 1,5 napthalenediacetic acid

Then conversion of the OH groups in the acetic acid to H by chlorinating or brominating them and then replace the Chlorine/Bromine with Hydrogen using H2/Pd in the presence of BaSO4.

Then it could be cyclized with H2SO4 to form the molecule
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[*] posted on 21-10-2018 at 00:30


Quote:
I also do not see five chiral centres, havent a clue why Atara stated that, perhaps an oversight on his part.


I didn't say anything about five chiral centers or for that matter anything about chirality at all.

I'm not sure about the Birch reduction of 1,5-naphthalenediols. I can't find anything like it in the literature. Most general references tell me that usually only one ring of naphthalene is reduced, though. That alone suggests that the method needs to be revised a little. Or maybe it's just a stoichiometry thing.

But the perhydrogenation of that naphthalene ought to be achievable somehow. What's less clear is what we end up with afterwards, and how to turn that into what we want.




[Edited on 04-20-1969 by clearly_not_atara]
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