Conjugate Addition and Ether Formation

In summary, the conversation discusses molecule B and problem number 8, second molecule. The student asks about the use of acid in carbonyl or conjugate addition and the potential for a carbonyl addition with LiMe. The expert confirms that LiMe is a hard nucleophile and suggests drawing the initially-formed product before adding acid. The student also asks about producing an ether from conjugate addition, to which the expert gives a hint from the previous problem and suggests a possible two-step process.
  • #1
lo2
55
0

Homework Statement



http://i43.tinypic.com/nxvw41.jpg

Ok here it is molecule B.

http://i39.tinypic.com/333aaro.jpg

Ok and here it is problem nr. 8, second molecule.


Homework Equations



No equations needed.

The Attempt at a Solution



1)
So why is it that we do not add any acid here, as far as I know one need acid, in order to do a succesfull carbonlyl or conjugate addition, right? So how come? And because it is LiMe (which is a hard nucleophile) I think it will be a carbonyl addition, so am I right?

2)
Well I did not really get that far as I am really not sure how to produce an ether from conjugate addition... So how to?

Edit: images replaced with links; please don't post large images as they are breaking forum formatting.
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
lo2 said:

Homework Statement



http://i43.tinypic.com/nxvw41.jpg

Ok here it is molecule B.

http://i39.tinypic.com/333aaro.jpg

Ok and here it is problem nr. 8, second molecule.


Homework Equations



No equations needed.

The Attempt at a Solution



1)
So why is it that we do not add any acid here, as far as I know one need acid, in order to do a succesfull carbonlyl or conjugate addition, right? So how come? And because it is LiMe (which is a hard nucleophile) I think it will be a carbonyl addition, so am I right?

Yes, you are correct. Why can't you draw the initially-formed product (before acid is added)?

2)
Well I did not really get that far as I am really not sure how to produce an ether from conjugate addition... So how to?

There is a hint in the previous problem. I'm not sure how to do this in one step but it's possible in two.
 

1. What is a conjugate addition problem?

A conjugate addition problem is a type of chemical reaction where a nucleophile (electron-rich species) attacks an electron-deficient carbon atom in the presence of a base. This reaction often involves the addition of a carbon-carbon double bond to the nucleophile, resulting in an extended conjugated system.

2. What types of nucleophiles are commonly used in conjugate addition reactions?

Some common nucleophiles used in conjugate addition reactions include organometallic reagents (such as Grignard reagents and organolithium compounds), enolates, and amines. The choice of nucleophile often depends on the specific reaction conditions and desired product.

3. What are the key steps in a conjugate addition reaction?

The key steps in a conjugate addition reaction are the formation of a nucleophilic species, the attack of the nucleophile on the electron-deficient carbon atom, and the elimination of a leaving group. The reaction may also involve proton transfer and/or rearrangement of double bonds.

4. How does the choice of solvent affect a conjugate addition reaction?

The choice of solvent can greatly influence the outcome of a conjugate addition reaction. For example, polar protic solvents (such as water or alcohols) tend to decrease the reactivity of the nucleophile, while polar aprotic solvents (such as DMF or DMSO) can enhance the reaction rate. Nonpolar solvents may also be used to promote the formation of certain products.

5. What are some key applications of conjugate addition reactions?

Conjugate addition reactions have a wide range of applications in organic synthesis. They are commonly used to form carbon-carbon and carbon-heteroatom bonds, as well as to synthesize complex molecules with extended conjugated systems. These reactions are also valuable in the production of pharmaceuticals, natural products, and materials.

Similar threads

  • Biology and Chemistry Homework Help
Replies
3
Views
4K
  • Biology and Chemistry Homework Help
Replies
2
Views
5K
  • Biology and Chemistry Homework Help
Replies
16
Views
33K
Replies
1
Views
1K
  • Science and Math Textbooks
Replies
4
Views
5K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
2K
  • Other Physics Topics
Replies
25
Views
3K
  • Introductory Physics Homework Help
Replies
3
Views
10K
Replies
4
Views
3K
Back
Top