Questions tagged [protecting-groups]

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Synthesis of tripeptide using Merrifield peptide synthesis procedure - Inclusion of asparagine

I am supposed to synthesize tripeptide, $\mathrm{Ala-Asn-Phe}$, using Merrifield peptide synthesis procedure. Accordingly, I have done followings: Attached protected $\mathrm{Phe}$ as the first ...
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0answers
38 views

Charactaristics of Certain Hydroxyl Protecting Groups

I have been reading through Philip J. Kocienski's book Protecting Groups to try to better understand some of the characteristics of hydroxy protecting groups. I am looking to understand the ...
0
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0answers
47 views

Hydroxy Protecting Groups that are not Cleaved Under Acidic Conditions

I am currently designing a synthesis requiring the use of hydroxy protecting groups. The problem I am having is that the protecting group must be able to survive highly acidic conditions. I would have ...
6
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2answers
292 views

How are neutral amines effective bases in organic chemistry?

I have found it to be rather strange that neutral amines, such as triethylamine or DIPEA, find applications in organic chemistry in deprotonating alcohols or even α-carbonyl compounds. Amines are ...
0
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1answer
36 views

Synthesis for turning synephrenine into N-methylphenethylamine

I am trying to devise a synthesis to change synephrine (4-[1-hydroxy-2-(methylamino)ethyl]phenol) into N-methylphenethylamine. I was figuring that I could remove the hydroxyl group attached to the ...
0
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0answers
104 views

t-Boc protection of amide (urea)

I'm trying to prepare protected urea and I'd like to protect it with some alkali stable PG. Is it possible to protect urea with t-Boc? Or is there another way to get boc-protected urea?
0
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1answer
93 views

Wittig reaction with an alkyl dibromide

Recently, I have come across a problem, in which a ketone needs to be converted into an alkene. However, in the alkene product, there is also another bromide functional group, at the end of the alkyl ...
0
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1answer
97 views

Alcohol protection with ethers

Various ethers are used for hydroxyl protection. My question is about their removal. I know that there are various methods but I want to specify on the use of acids. Certain groups are removed easily ...
2
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2answers
229 views

Can protection group be used in a Wolff–Kishner reaction?

How can I modify the ozonolysis of cyclohexene such that one of the aldehyde groups of the product, adipaldehyde, is efficiently protected as a base stable protecting group? I know that attempting to ...
3
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1answer
4k views

What happens to the t-butyl cation in the TFA deprotection of a t-butyl ester?

I am a first-year chemistry graduate student and I am currently learning how to synthesize proteins. I have reached a stage in the process where I need to deprotect a carboxylic acid moiety protected ...
2
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1answer
142 views

Decomposition of acetonide protecting group in chloroform

Today I purified my compound containing an acetonide protected diol. I took an NMR sample and it looked great, but because I have only little amount of the compound, I put the sample back into the ...
3
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1answer
402 views

How to form an acetal from an enol ether?

I am having trouble understanding how the protecting group (ethylene glycol) is applied to the alkene next to the ether of highlighted step above. I thought maybe TsOH protonates the alkene as seen in ...
-1
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1answer
522 views

Trimethylsilyl iodide - Alkyne Reaction

I have synthesized the molecule below possessing a doubly, boc protected heterocyclic amine and a terminal alkyne. Upon attempting a TFA/$\ce{CH2Cl2}$ Boc deprotection I believe my alkyne is being ...
0
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3answers
886 views

What are protecting groups in organic chemistry? [closed]

My textbook does not give a very good explanation of what protecting groups are, how they are made, or how they function in Grignard reactions and others. It just gives a couple of examples of ...
5
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3answers
506 views

Effect of protecting group on diastereoselectivity of LiAlH4 reduction of α-hydroxyketones

In the reactions above, taken from Tetrahedron Lett. 1982, 23 (23), 2355–2358, the choice of protecting group on the α-hydroxyl group has a large influence on the diastereoselectivity of reduction. ...
1
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1answer
370 views

Can an ether be selectively hydrolysed in the presence of an ester?

What reaction, or protection/deprotection can be used to transform the ether group of a molecule that also has an ester compound into an alcohol while keeping the ester unchanged? For example: The ...
3
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0answers
96 views

How can the ketone in a β-ketoester be protected during hydride reduction?

I am supposed to find what X is. I know that $\ce{LiAlH_4}$ will convert all carbonyl groups to alcohols, and the ester group is being reduced. The only way of ending up with a ketone that I can think ...
15
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1answer
4k views

By what mechanism do acids deprotect primary silyl ethers?

Standard protocols report the selective deprotection of primary silyl ethers in the presence of secondary silyl ethers under acidic conditions, as exemplary shown in scheme 1, a reaction by Hartmann ...
6
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1answer
2k views

Can a benzyl ether be removed in the presence of an ester?

I'd like to deprotect a benzyl group for a Fráter–Seebach alkylation. Would it be possible to do this with a Birch reduction using Li/NH3 (or Na/NH3), without also reducing the ester carbonyl group? ...