kyanite
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Protecting groups
Protecting groups are bits of chemical groups that can be easily added/removed to a compound. Most importantly, they are protectors of the part they
are attached to when you don't want a reaction to change that section.
Here is a good example from the online version of "Organic Chemistry" 5th ed. by Francis A. Carey.
http://www.chem.ucalgary.ca/courses/350/Carey5th/Ch17/ch17-3-4-3.html
It has a good example of a ketone protection, with the cup and everything 
www.infochembio.ethz.ch/pdf/ProtGroups.pdf Here is a list of groups I found.
There are alot of ethers on there, and I was wondering if an ether addition to an alkene would be considered a protecting group as I want to nitrate
an olefin but keep the double bond.
Is there an expert here on the subject that could help clarify things?
Edit: Url
[Edited on 21-10-2004 by kyanite]
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Marvin
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I get the feeling you have a very specific product in mind, and a very specific starting material. Why dont you try telling us what you are trying to
do because "nitrating an olefin while keeping the double bond" makes no sense.
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kyanite
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You got me , I did have a specific starting material in mind. It's
vinylbenzene -styrene monomer, and I think this is what you guessed it would be.
Sorry for the confusion, and not being specific enough,
Styrene monomer is a benzene ring with CH=CH2 at the one postion. What I was worried about was that the NO2 would be a too strong of a electrophilic
and join with the double bond.
I am curious about blocking groups since they seem to be easy to use-useful tools.
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Marvin
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The nitrostyrenes can be made but different starting materials need to be used. The other thing is they dont polymerise oweing to the nitro groups
inhibiting properites.
See Urbanski volume 1 for information on the polynitrostyrenes (made by nitrating the polymer) and the nitrostyrenes (made by more cunning methods).
If you are after a nitrostyrene for another reason, say to reduce to an amine Strike's total synthesis might be of use but I'm unsure here.
Try telling us exactly what you want to make. Theres no generic protecting group for every reaction and very few useful methods for double bonds.
Making a dibromide comes to mind and then getting back the double bond by reaction with zinc comes to mind but its not very stable.
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kyanite
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Well it seems that I have no more need of nitro styrene, I have found a synth that seems to be a lot more straight forward, using cinnaminic acid,
hypochlorite, sodium enthoxide and a nitration.
I had wanted to make nitro styrene to synth Indole. Sorry, I really need to be more descriptive in the future.
Thank you for showing me where I should start looking into protecting groups, dibromide should be a good start.
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