3. Draw all products for the following reactions. For your products, write whether the nucleophile added to the Re face or Si face of the starting material. a. b. 1) LIAIH4 2) H™ HOI.... 1) CH3CH2Li 2) H+ c) Determine whether the nucleophile added to the Re face or Si face of benzaldehyde.
Basics in Organic Reactions Mechanisms
In organic chemistry, the mechanism of an organic reaction is defined as a complete step-by-step explanation of how a reaction of organic compounds happens. A completely detailed mechanism would relate the first structure of the reactants with the last structure of the products and would represent changes in structure and energy all through the reaction step.
Heterolytic Bond Breaking
Heterolytic bond breaking is also known as heterolysis or heterolytic fission or ionic fission. It is defined as breaking of a covalent bond between two different atoms in which one atom gains both of the shared pair of electrons. The atom that gains both electrons is more electronegative than the other atom in covalent bond. The energy needed for heterolytic fission is called as heterolytic bond dissociation energy.
Polar Aprotic Solvent
Solvents that are chemically polar in nature and are not capable of hydrogen bonding (implying that a hydrogen atom directly linked with an electronegative atom is not found) are referred to as polar aprotic solvents. Some commonly used polar aprotic solvents are acetone, DMF, acetonitrile, DMSO, etc.
Oxygen Nucleophiles
Oxygen being an electron rich species with a lone pair electron, can act as a good nucleophile. Typically, oxygen nucleophiles can be found in these compounds- water, hydroxides and alcohols.
Carbon Nucleophiles
We are aware that carbon belongs to group IV and hence does not possess any lone pair of electrons. Implying that neutral carbon is not a nucleophile then how is carbon going to be nucleophilic? The answer to this is that when a carbon atom is attached to a metal (can be seen in the case of organometallic compounds), the metal atom develops a partial positive charge and carbon develops a partial negative charge, hence making carbon nucleophilic.
![**Organic Chemistry Reactions and Stereochemistry Analysis**
**Question 3: Draw all products for the following reactions. For your products, write whether the nucleophile added to the Re face or Si face of the starting material.**
**a.**
- **Reaction Scheme:**
- Starting Material: A compound with a ketone group attached to a phenyl ring (benzylacetone).
- Reagents:
1) LiAlH4
2) H⁺
**Explanation:**
This reaction is a reduction of the ketone using lithium aluminum hydride (LiAlH4) followed by an acid work-up to obtain an alcohol. The stereochemistry needs to be analyzed to determine whether the addition occurred on the Re or Si face.
**b.**
- **Reaction Scheme:**
- Starting Material: An aromatic ketone compound.
- Reagents:
1) CH₃CH₂Li
2) H⁺
**Explanation:**
Here, the ethyl lithium acts as a nucleophile, adding to the carbonyl carbon of the ketone. The product will be an alcohol after protonation. The analysis of Re face or Si face addition is necessary to provide the stereochemical outcome.
**c. Determine whether the nucleophile added to the Re face or Si face of benzaldehyde.**
A structure of a product is shown with an alcohol group and benzaldehyde derivative, which implies that stereochemistry has been established. The question asks to evaluate the stereospecificity of the nucleophilic addition to determine the face of the original benzaldehyde that was attacked.
**Note:** In organic chemistry, the terms 'Re face' and 'Si face' refer to the two different faces of a planar sp² hybridized carbon atom in a double bond or aromatic system. The determination of which face is attacked by a nucleophile can influence the stereochemistry of the resulting compound. Understanding these concepts is crucial for predicting and explaining the outcomes of reactions in stereochemistry.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Ff57d3743-5e44-4060-83da-5d90a37d31c6%2Ff9dae30f-042e-4cbd-a477-b6520f59e7f1%2F6f0pqbh_processed.png&w=3840&q=75)
![](/static/compass_v2/shared-icons/check-mark.png)
Trending now
This is a popular solution!
Step by step
Solved in 4 steps with 3 images
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
![Chemistry](https://www.bartleby.com/isbn_cover_images/9781305957404/9781305957404_smallCoverImage.gif)
![Chemistry](https://www.bartleby.com/isbn_cover_images/9781259911156/9781259911156_smallCoverImage.gif)
![Principles of Instrumental Analysis](https://www.bartleby.com/isbn_cover_images/9781305577213/9781305577213_smallCoverImage.gif)
![Chemistry](https://www.bartleby.com/isbn_cover_images/9781305957404/9781305957404_smallCoverImage.gif)
![Chemistry](https://www.bartleby.com/isbn_cover_images/9781259911156/9781259911156_smallCoverImage.gif)
![Principles of Instrumental Analysis](https://www.bartleby.com/isbn_cover_images/9781305577213/9781305577213_smallCoverImage.gif)
![Organic Chemistry](https://www.bartleby.com/isbn_cover_images/9780078021558/9780078021558_smallCoverImage.gif)
![Chemistry: Principles and Reactions](https://www.bartleby.com/isbn_cover_images/9781305079373/9781305079373_smallCoverImage.gif)
![Elementary Principles of Chemical Processes, Bind…](https://www.bartleby.com/isbn_cover_images/9781118431221/9781118431221_smallCoverImage.gif)