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moonfisher
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Boxwood odor
You know the smell of boxwood in the summer sun? Its an interesting odor. Turns out its made of 4-methyl-4-mercaptopentan-2-one and 3-mercaptohexyl
acetate.
4-methyl-4-mercaptopentan-2-one
Uhhh...
3-mercaptohexyl acetate- seems easy enough: 3-mercaptohexanol and acetic acid esterification. Just how to make 3-mercaptohexanol? Sodium hydrosulfate
on 3-hexanol a la https://en.wikipedia.org/wiki/Thiol#Preparation?
Didnt find anything bout extractions, so is there a way these can be easily synthesized? Aren't mercaptans THE stinkers? (I also have little
experience in org chem...)
It might be a fun project.
Sources:
https://books.google.com/books?id=1KeJCS0in_IC&pg=PT98&a...
https://books.google.com/books?id=EaLysIpGTK0C&pg=PA221&...
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Magpie
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I like the smell of boxwood in the summer. When I see a hedge of boxwood I know I will enjoy walking along side of it.
When I landscaped my front yard a few years back I planted 5 boxwood under my front window in hopes of growing a hedge. But they are struggling and
one died. I'm not sure what is wrong. Maybe there's not enough sulfur in my soil.
The single most important condition for a successful synthesis is good mixing - Nicodem
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hyfalcon
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I think you're on the right track. Most foundations have bits of mortar in the ground. This causes the soil to go alkali. Sulfur would be a good
cure, so would cottonseed meal.
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CuReUS
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S is more nucleophilic than O,so it will get acetylated predominantly.
Quote: | so is there a way these can be easily synthesized? |
here's my way
1.synthesis of gamma-butyrolactone from THF
http://pubs.acs.org/doi/abs/10.1021/op980028j
2.reaction of gamma-butyrolactone with ethylMgBr to give 6-hydroxyhexan-3-one
https://www.thieme-connect.com/products/ejournals/abstract/1...
3.acetylation of 6-hydrohexan-3-one using any acetylating agent
4.conversion of ketone to thiol via the thioketal to get the target compound
http://www.orgsyn.org/demo.aspx?prep=cv7p0124
[Edited on 13-3-2016 by CuReUS]
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clearly_not_atara
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From levulinic acid:
1. cycloenolization with acetic anhydride/H2SO4 to 5-methyl-2-furanone.
2. alpha-dimethylation with Li(iPr)2N/Me2CO3 to the 3,3-dimethyl-(1)
3. Hydrolysis to 2,2-dimethyl-5-oxohexanoic acid
4. Precipitation of the silver salt with AgNO3 and bromodecarboxylation to 4-methyl-4-bromo-2-pentanone
5. Na2S2O3 followed by TsOH/H2O and extraction of 4-mercapto-4-methyl-2-pentanone with np solvent
Also generally thioesters are formed kinetically but esters are preferred thermodynamically due to stronger charge delocalization. Under the right
conditions you'll get the O-acetyl thiol.
[Edited on 13-3-2016 by clearly_not_atara]
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moonfisher
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Quote: Originally posted by Magpie ![](images/xpblue/lastpost.gif) | I like the smell of boxwood in the summer. When I see a hedge of boxwood I know I will enjoy walking along side of it.
When I landscaped my front yard a few years back I planted 5 boxwood under my front window in hopes of growing a hedge. But they are struggling and
one died. I'm not sure what is wrong. Maybe there's not enough sulfur in my soil. |
Thankfully I am a "plant nerd"! What side of the building are they growing on? How close to the foundation? What's the texture of the soil? And how is
your climate like?
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moonfisher
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Oops! thats the kind of mistake I didnt want to make; although acetylization at that location would be interesting. Thanks for the references.
Step 2 looks tricker. Grignards are cool, but a pain in the ass.
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Magpie
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Quote: Originally posted by moonfisher ![](images/xpblue/lastpost.gif) |
Thankfully I am a "plant nerd"! What side of the building are they growing on? How close to the foundation? What's the texture of the soil? And how is
your climate like? |
West, 12 inches, sandy, desert. Sprinklers water these bushes everyday from about April 1 to Oct 1.
The single most important condition for a successful synthesis is good mixing - Nicodem
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moonfisher
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Quote: Originally posted by clearly_not_atara ![](images/xpblue/lastpost.gif) | From levulinic acid:
1. cycloenolization with acetic anhydride/H2SO4 to 5-methyl-2-furanone.
2. alpha-dimethylation with Li(iPr)2N/Me2CO3 to the 3,3-dimethyl-(1)
3. Hydrolysis to 2,2-dimethyl-5-oxohexanoic acid
4. Precipitation of the silver salt with AgNO3 and bromodecarboxylation to 4-methyl-4-bromo-2-pentanone
5. Na2S2O3 followed by TsOH/H2O and extraction of 4-mercapto-4-methyl-2-pentanone with np solvent
Also generally thioesters are formed kinetically but esters are preferred thermodynamically due to stronger charge delocalization. Under the right
conditions you'll get the O-acetyl thiol.
[Edited on 13-3-2016 by clearly_not_atara] |
Thanks! Never would have came up with that myself. Li(iPr)2N sounds like fun
Well, good chemists shouldn't lick their fingers, anyways
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Bert
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Quote: Originally posted by Magpie ![](images/xpblue/lastpost.gif) | Quote: Originally posted by moonfisher ![](images/xpblue/lastpost.gif) |
Thankfully I am a "plant nerd"! What side of the building are they growing on? How close to the foundation? What's the texture of the soil? And how is
your climate like? |
West, 12 inches, sandy, desert. Sprinklers water these bushes everyday from about April 1 to Oct 1. |
What side of the building, how many hours of direct sun light a day to.they get?
Your soil was likely alkaline to start, much of the USA's dessert Southwest is.
Lime from the fresh cement compounds the alkalinity, and hard sprinkler water may well be adding yet more alkalinity due to build up of soluble
carbonates. Try a good shot of ammonium sulfate worked into the soil around one of the the plants, cover an area 2X as wide as the drip line of the
shrub... if that works, you could add granite dust or Sulfur, along with organic material such as old pine needles worked into the top layer of soil
for a long term solution to the high pH issue.
Another big plant nerd here!
[Edited on 14-3-2016 by Bert]
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2. List any points of agreement (especially if they are not matters of general or widespread agreement).
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CuReUS
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nobody read this reference carefully ,or they would have pointed out the horrible blunder that I made ![:D](./images/smilies/biggrin.gif)
in that case, another method has to be adopted to convert the ketone to thiol.Unfortunately I could find any good methods. If anyone knows of a better
method please post it here .If a good method is not found,the only thing that can be done is to reduce the ketone to alcohol using NaBH4
and then do atara's 5th step- Na2S2O3 followed by TsOH/H2O to get the mercaptan.(hoping that the TsOH/H2O step does not hydrolyse the ester
)
The method I found is this
http://www.google.co.in/patents/US2402613
Quote: | Example VII One hundred grams of levulinic acid, 60 grams of sulfur, and 15 grams of cobalt sulfide catalyst prepared as described under Example I are
reacted with hydrogen at 1000 to 2000 lbs/sq. in. pressure and a temperature of 150 to 175 C. in a small autoclave. After six hours the absorption of
hydrogen has ceased. The products of the reaction are then subjected to fractional distillation after removal of the catalyst by filtration. This
material consists principally of the lactone of 4-mercaptovaleric acid formed by cyclization of the 4-mercaptovaleric acid. |
also I am sorry to say,but due to a mistake in nomenclature,my synthesis gives 4-mercaptohexyl acetate instead of 3-mercaptohexylacetate![:D](./images/smilies/biggrin.gif)
so instead of using 6-hydroxyhexan-3-one,1-hydroxyhexan-3-one has to be used .That is made by reaction of 4-hydroxybutan-2-one with iodoethane
http://www.chemsink.com/reaction/1758390/.
After that the reaction is the same.I will come up with a route to 4-hydroxybutan-2-one later![;)](./images/smilies/wink.gif)
Quote: | Also generally thioesters are formed kinetically but esters are preferred thermodynamically due to stronger charge delocalization. Under the right
conditions you'll get the O-acetyl thiol. |
atara I have told you before also ,please provide references .What do you mean by "right conditions" ?
moonfisher ,I also realised that making the compound itself is not enough,you also have to make the correct enantiomer.Since its a natural product,If
you don't have the right enantiomer,you won't get the desired smell ![:)](./images/smilies/smile.gif)
[Edited on 14-3-2016 by CuReUS]
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moonfisher
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Quote: Originally posted by Bert ![](images/xpblue/lastpost.gif) | Quote: Originally posted by Magpie ![](images/xpblue/lastpost.gif) | Quote: Originally posted by moonfisher ![](images/xpblue/lastpost.gif) |
Thankfully I am a "plant nerd"! What side of the building are they growing on? How close to the foundation? What's the texture of the soil? And how is
your climate like? |
West, 12 inches, sandy, desert. Sprinklers water these bushes everyday from about April 1 to Oct 1. |
What side of the building, how many hours of direct sun light a day to.they get?
Your soil was likely alkaline to start, much of the USA's dessert Southwest is.
Lime from the fresh cement compounds the alkalinity, and hard sprinkler water may well be adding yet more alkalinity due to build up of soluble
carbonates. Try a good shot of ammonium sulfate worked into the soil around one of the the plants, cover an area 2X as wide as the drip line of the
shrub... if that works, you could add granite dust or Sulfur, along with organic material such as old pine needles worked into the top layer of soil
for a long term solution to the high pH issue.
Another big plant nerd here!
[Edited on 14-3-2016 by Bert] |
Yes! We can nerd together!
Bert is right- the quick-draining sand doesnt help either: the local soil is clay, and they grow like weeds. I am in the wet, temperate NYC region.
Even here, exposure to hot afternoon sun puts stress on them. Copious amounts of organic matter is needed- nutrient retention by the soil and
absorption by the plant can very substantially with pH, and something to filter the light a little bit, it you are at a high elevation and farther
south. It would also save on water costs.
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moonfisher
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Quote: Originally posted by CuReUS ![](images/xpblue/lastpost.gif) |
nobody read this reference carefully ,or they would have pointed out the horrible blunder that I made ![:D](./images/smilies/biggrin.gif)
in that case, another method has to be adopted to convert the ketone to thiol.Unfortunately I could find any good methods. If anyone knows of a better
method please post it here .If a good method is not found,the only thing that can be done is to reduce the ketone to alcohol using NaBH4
and then do atara's 5th step- Na2S2O3 followed by TsOH/H2O to get the mercaptan.(hoping that the TsOH/H2O step does not hydrolyse the ester
)
The method I found is this
http://www.google.co.in/patents/US2402613
Quote: | Example VII One hundred grams of levulinic acid, 60 grams of sulfur, and 15 grams of cobalt sulfide catalyst prepared as described under Example I are
reacted with hydrogen at 1000 to 2000 lbs/sq. in. pressure and a temperature of 150 to 175 C. in a small autoclave. After six hours the absorption of
hydrogen has ceased. The products of the reaction are then subjected to fractional distillation after removal of the catalyst by filtration. This
material consists principally of the lactone of 4-mercaptovaleric acid formed by cyclization of the 4-mercaptovaleric acid. |
also I am sorry to say,but due to a mistake in nomenclature,my synthesis gives 4-mercaptohexyl acetate instead of 3-mercaptohexylacetate![:D](./images/smilies/biggrin.gif)
so instead of using 6-hydroxyhexan-3-one,1-hydroxyhexan-3-one has to be used .That is made by reaction of 4-hydroxybutan-2-one with iodoethane
http://www.chemsink.com/reaction/1758390/.
After that the reaction is the same.I will come up with a route to 4-hydroxybutan-2-one later![;)](./images/smilies/wink.gif)
Quote: | Also generally thioesters are formed kinetically but esters are preferred thermodynamically due to stronger charge delocalization. Under the right
conditions you'll get the O-acetyl thiol. |
atara I have told you before also ,please provide references .What do you mean by "right conditions" ?
moonfisher ,I also realised that making the compound itself is not enough,you also have to make the correct enantiomer.Since its a natural product,If
you don't have the right enantiomer,you won't get the desired smell ![:)](./images/smilies/smile.gif)
[Edited on 14-3-2016 by CuReUS] |
Thanks for pointing out your errors- it would have taken me MUCH longer, if at all to find them (org chem is not my forte). The entiomer problem is a
big issue- no source cites which one is the boxwood one! It will be a learning experience!
These reactions look quite interesting actually. "hoping that the TsOH/H2O step does not hydrolyse the ester" That was something I did
notice a bit later on.
Quote: |
eacted with hydrogen at 1000 to 2000 lbs/sq. in. pressure and a temperature of 150 to 175 C
|
heh...
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Magpie
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Quote: Originally posted by Bert ![](images/xpblue/lastpost.gif) |
What side of the building, how many hours of direct sun light a day to.they get?
Your soil was likely alkaline to start, much of the USA's dessert Southwest is.
Lime from the fresh cement compounds the alkalinity, and hard sprinkler water may well be adding yet more alkalinity due to build up of soluble
carbonates. Try a good shot of ammonium sulfate worked into the soil around one of the the plants, cover an area 2X as wide as the drip line of the
shrub... if that works, you could add granite dust or Sulfur, along with organic material such as old pine needles worked into the top layer of soil
for a long term solution to the high pH issue.
Another big plant nerd here!
|
Quote: Originally posted by moonfisher ![](images/xpblue/lastpost.gif) |
Yes! We can nerd together!
Bert is right- the quick-draining sand doesnt help either: the local soil is clay, and they grow like weeds. I am in the wet, temperate NYC region.
Even here, exposure to hot afternoon sun puts stress on them. Copious amounts of organic matter is needed- nutrient retention by the soil and
absorption by the plant can very substantially with pH, and something to filter the light a little bit, it you are at a high elevation and farther
south. It would also save on water costs. |
The plants are on the West side of the building. They get probably 6hrs/day direct sunlight.
I scraped up some soil from the surface, added some distilled water, and measured the pH. It's neutral to slightly acid.
I bought a 20lb bag of ammonium sulfate for $10. I'll be adding that to the soil around the plants.
Thanks to both of you for your advice.
The single most important condition for a successful synthesis is good mixing - Nicodem
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Dr.Bob
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I can send you a box of nice red clay from NC if you want more moisture retention and some nice acidic dirt... It also makes nice bricks.
As is often the case, natural product extraction is likely much more practical than total synthesis, although even better might be to move the desired
genes into another organism and just express them there. That seems to be the new way to make stuff.
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CuReUS
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I have come up with some routes to make 4-hydroxybutan-2-one
1. from 2-methyloxetane: reaction of this with fenton' reagent should open up the ring,followed by a selective oxidation of the secondary OH over the
primary OH to give 4-hydroxybutan-2-one.
2. by aldol addition: from acetone and HCHO.I found a method to make b-hydroxyketones but they don't use HCHO.
https://www.thieme-connect.com/products/ejournals/abstract/1...
or you could convert acetone to its lithium enolate using LDA and then react with HCHO to get 4-hydroxybutan-2-one
you can also see this for more examples
http://www.organic-chemistry.org/namedreactions/aldol-additi...
these conditions are possible in an autoclave
moonfisher,I have spent a considerable time and effort to come up with these reactions and I am sure atara has too. So please try them out atleast on
a small scale while you wait for your plants to grow![;)](./images/smilies/wink.gif)
[Edited on 15-3-2016 by CuReUS]
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moonfisher
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CuReUS,
Don't worry! Ill do it! (eventually )
Im planning to make the hydroxybutanone this weekend, starting to write the background for the writeup.
Then, the ethyl iodide- ChemPlayer made a vid with aluminium foil, so I will do that one. Is it lachrymatory? The MSDS I found said it is irritating
to eyes and skin, do not inhale fumes but nothing specific.
[Edited on 15-3-2016 by moonfisher]
Well, good chemists shouldn't lick their fingers, anyways
-Life advice from Sir Martyn
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CuReUS
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thaaaaank yoou ![:)](./images/smilies/smile.gif) ![:)](./images/smilies/smile.gif)
Quote: | Then, the ethyl iodide- ChemPlayer made a vid with aluminium foil, so I will do that one. Is it lachrymatory? |
not as far as I know.
which method will you use to make the hydroxybutanone ? If you are going to use the LDA method,I have an idea .First react the lithium enolate of
acetone with ethyl iodide to get 2-pentanone .Then make the lithium enolate again and react that with HCHO to get 1-hydroxyhexan-3-one.
The reason is that if you make the hydroxybutanone first,then do the ethyl iodide reaction,some LDA will get wasted reacting with the OH instead of
forming the enolate with the ketone.
you could also make 2-pentanone using grignard reaction between n-propylMgBr and acetonitrile.
di isopropylamine is found in a herbicide called roundup. reacting that with BuLi in dry THF gives LDA.
http://www.sciencemadness.org/talk/viewthread.php?tid=28429
[Edited on 16-3-2016 by CuReUS]
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moonfisher
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Quote: Originally posted by CuReUS ![](images/xpblue/lastpost.gif) |
thaaaaank yoou ![:)](./images/smilies/smile.gif) ![:)](./images/smilies/smile.gif)
Quote: | Then, the ethyl iodide- ChemPlayer made a vid with aluminium foil, so I will do that one. Is it lachrymatory? |
not as far as I know.
which method will you use to make the hydroxybutanone ? If you are going to use the LDA method,I have an idea .First react the lithium enolate of
acetone with ethyl iodide to get 2-pentanone .Then make the lithium enolate again and react that with HCHO to get 1-hydroxyhexan-3-one.
The reason is that if you make the hydroxybutanone first,then do the ethyl iodide reaction,some LDA will get wasted reacting with the OH instead of
forming the enolate with the ketone.
you could also make 2-pentanone using grignard reaction between n-propylMgBr and acetonitrile.
di isopropylamine is found in a herbicide called roundup. reacting that with BuLi in dry THF gives LDA.
http://www.sciencemadness.org/talk/viewthread.php?tid=28429
[Edited on 16-3-2016 by CuReUS] |
I won't be working with organolithium just yet. I can try it in a school lab after Easter, but not at home! I'd stick with the Grignard.
I'm looking at the aldol method. I do want to try the LDA. (I knew the RoundUp would come in useful lol.)
Well, good chemists shouldn't lick their fingers, anyways
-Life advice from Sir Martyn
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chemrox
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A very fruitful thread here. Going back to boxwood: thanks for the information. I had no idea a mercaptan could be involved in a pleasant odor. I love
smelly compounds and make them from time to time just for fun. Why we're here right? Anyway, wouldn't getting to the boxwood smells involve some
really unpleasant odors in your lab and neighborhood? You might be less welcome than a meth lab.
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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CuReUS
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Quote: Originally posted by moonfisher ![](images/xpblue/lastpost.gif) |
I won't be working with organolithium just yet. I can try it in a school lab after Easter, but not at home! I'd stick with the Grignard.
I'm looking at the aldol method. I do want to try the LDA.
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I am a little confused. by organolithium you mean BuLi ,right ? but you need to use it to make LDA. Otherwise you have to buy LDA.
what grignard are you talking about ? Quote: Originally posted by chemrox ![](images/xpblue/lastpost.gif) | wouldn't getting to the boxwood smells involve some really unpleasant odors in your lab and neighborhood? You might be less welcome than a meth lab.
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That's why I am trying to introduce the SH group in the last step.
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moonfisher
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Quote: Originally posted by CuReUS ![](images/xpblue/lastpost.gif) | Quote: Originally posted by moonfisher ![](images/xpblue/lastpost.gif) |
I won't be working with organolithium just yet. I can try it in a school lab after Easter, but not at home! I'd stick with the Grignard.
I'm looking at the aldol method. I do want to try the LDA.
|
I am a little confused. by organolithium you mean BuLi ,right ? but you need to use it to make LDA. Otherwise you have to buy LDA.
what grignard are you talking about ? Quote: Originally posted by chemrox ![](images/xpblue/lastpost.gif) | wouldn't getting to the boxwood smells involve some really unpleasant odors in your lab and neighborhood? You might be less welcome than a meth lab.
|
That's why I am trying to introduce the SH group in the last step. |
The Grignard is propylMgBr, and the organs lithium is BuLi. Sorry for my sloppy nomenclature.
Looking at the schemes, these mercaptans aren't that stinky. One has a bitter, grapefruit odor, while the other has something between cat urine and
pine. Although it is a little crowded where I live, there is also largeish stretches of swamp, if worse comes to worse!
Well, good chemists shouldn't lick their fingers, anyways
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CuReUS
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after a lot of searching,I have finally found a method to convert the ketone to thiol via reduction of the thione
thioketones(thiones) can be made in 3 ways:
1. the classical H2S/HCl method
https://books.google.co.in/books?id=0F3FIRgWwhQC&pg=PA18...
http://orgsyn.org/demo.aspx?prep=CV4P0927
2.phosphorus pentasulfide method
http://pubs.rsc.org/en/content/articlelanding/1993/cs/cs9932...
according to this paper,ketones can be selectively converted to thioketones in the presence of esters.This paper also talks about the
H2S/HCl method and also gives reference for the reduction of thiones to thiols using NaBH4.
But in another paper it is given that P2S10 reacts with esters
http://pubs.acs.org/doi/abs/10.1021/cr900243d
another reference for pentasulphide- Gattermann, ibid. 28, 2877 (1895)
3.ethyl thioacetate method
couldn't find the paper,try to find it - Mitra, J. Indian Chem. Soc. 9, 637 (1932) [C. A. 27, 3922 (1933)].
a paper on the synthesis of di-tertbutyl ketone gives another reference for the classical method. but its a book,so I couldn't find it - https://www.jstage.jst.go.jp/article/bcsj1926/48/8/48_8_2403...
thioketones can also be reduced using sodium ethoxide ( pg 4/5 or pg 3721) https://www.jstage.jst.go.jp/article/bcsj1926/48/12/48_12_37...
but it can't be done in our compound because a transesterification reaction can occur
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moonfisher
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Thanks again! More to read.
Well, good chemists shouldn't lick their fingers, anyways
-Life advice from Sir Martyn
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clearly_not_atara
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http://en.wikipedia.org/wiki/Diacetone_alcohol
You're going through quite a few steps to make something that can be had in one step from acetone.
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