Based on conditions, identify where a nucleophilic attack would occur on the following epoxides. acidic basic IV II A. Tand III B. I and IV C. Il and III D. Il and IV

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**Title: Understanding Nucleophilic Attack on Epoxides under Different Conditions**

**Introduction:**
Epoxides are cyclic ethers with a three-membered ring, which makes them highly reactive. A common reaction involving epoxides is the ring-opening process that occurs via nucleophilic attack. The site of nucleophilic attack can vary depending on whether the conditions are acidic or basic.

**Question:**
Based on the conditions provided, identify where a nucleophilic attack would occur on the given epoxides.

**Diagrams and Explanation:**

- **Acidic Conditions (left diagram)**
  - The diagram shows an epoxide ring with the oxygen atom pointing upwards.
  - Arrow II points to the carbon of the epoxide adjacent to the oxygen atom, indicating a possible site of nucleophilic attack in acidic conditions.
  - Arrow I points to the other carbon of the epoxide ring also indicating it as a potential site for attack under acidic conditions.

- **Basic Conditions (right diagram)**
  - The diagram shows a similar epoxide structure again with the oxygen atom in an upward orientation.
  - Arrow IV points to the right-hand carbon of the epoxide, suggesting nucleophilic attack here under basic conditions.
  - Arrow III points to the left-hand carbon of the epoxide ring, indicating it as the site for attack under basic conditions.
  
**Multiple-choice Answers:**
  - **A. I and III**
  - **B. I and IV**
  - **C. II and III**
  - **D. II and IV**

In summary, nucleophilic attack on epoxides can vary based on the pH of the environment. Under acidic conditions, the attack usually occurs on the more substituted carbon. Under basic conditions, the attack generally takes place on the less substituted carbon.

**Conclusion:**
The correct answer to the question is **D. II and IV** which indicates the positions on the epoxide where nucleophilic attack occurs under acidic and basic conditions respectively. This helps understand how different conditions can influence the reactivity and outcome of chemical reactions involving epoxides.
Transcribed Image Text:**Title: Understanding Nucleophilic Attack on Epoxides under Different Conditions** **Introduction:** Epoxides are cyclic ethers with a three-membered ring, which makes them highly reactive. A common reaction involving epoxides is the ring-opening process that occurs via nucleophilic attack. The site of nucleophilic attack can vary depending on whether the conditions are acidic or basic. **Question:** Based on the conditions provided, identify where a nucleophilic attack would occur on the given epoxides. **Diagrams and Explanation:** - **Acidic Conditions (left diagram)** - The diagram shows an epoxide ring with the oxygen atom pointing upwards. - Arrow II points to the carbon of the epoxide adjacent to the oxygen atom, indicating a possible site of nucleophilic attack in acidic conditions. - Arrow I points to the other carbon of the epoxide ring also indicating it as a potential site for attack under acidic conditions. - **Basic Conditions (right diagram)** - The diagram shows a similar epoxide structure again with the oxygen atom in an upward orientation. - Arrow IV points to the right-hand carbon of the epoxide, suggesting nucleophilic attack here under basic conditions. - Arrow III points to the left-hand carbon of the epoxide ring, indicating it as the site for attack under basic conditions. **Multiple-choice Answers:** - **A. I and III** - **B. I and IV** - **C. II and III** - **D. II and IV** In summary, nucleophilic attack on epoxides can vary based on the pH of the environment. Under acidic conditions, the attack usually occurs on the more substituted carbon. Under basic conditions, the attack generally takes place on the less substituted carbon. **Conclusion:** The correct answer to the question is **D. II and IV** which indicates the positions on the epoxide where nucleophilic attack occurs under acidic and basic conditions respectively. This helps understand how different conditions can influence the reactivity and outcome of chemical reactions involving epoxides.
### Predict the Product for the Following Reactions

In this exercise, we are given two different reactions (Rxn I and Rxn II) involving an epoxide ring opening. The goal is to predict the major product formed after each reaction.

#### Reaction Schemes:

1. **Rxn I:**
   - **Starting Material:** An epoxide.
   - **Reagents:** H⁺ (Acid) and H₂O (Water).
   - **Product:** Two possible products, both are diols (compounds containing two hydroxyl groups).

    - Possible products:
        - A diol with hydroxyl groups on adjacent carbons.
        - Another diol isomer with hydroxyl groups on adjacent carbons but in a different stereochemical configuration.

2. **Rxn II:**
   - **Starting Material:** An epoxide.
   - **Reagents:** NaOCH₃ (Sodium methoxide) followed by H₂O (Water).
   - **Product:** Two possible products, one is a methoxy alcohol and the other is a diol.

    - Possible products:
        - A methoxy alcohol with the hydroxyl and methoxy groups on adjacent carbons.
        - A diol with hydroxyl groups on adjacent carbons but with different stereochemistry.

#### Reaction Conditions:
- **Rxn I:** Takes place under acidic conditions which typically leads to ring opening at the more substituted carbon due to protonation of the epoxide.
- **Rxn II:** Takes place under basic conditions involving NaOCH₃, resulting in nucleophilic attack at the less substituted carbon of the epoxide, followed by protonation with water.

#### Answer Choices:

The given products for each reaction are categorized from A to D to match the configurations detailed above. Each answer choice lists possible products for both Rxn I and Rxn II.

**Answer Choices:**

- **A:**
  - Rxn I: HO-CH₂-CH₂-OH
  - Rxn II: HO-CH₂-CH(OCH₃)-CH₃

- **B:**
  - Rxn I: (Two stereoisomers, hydroxyl groups in different configurations)
  - Rxn II: (Two stereoisomers involving CH₃O group instead of one hydroxyl group) 

- **C:**
  - Similar to answer choice A but with variations in stereochemistry for Rxn II products.
Transcribed Image Text:### Predict the Product for the Following Reactions In this exercise, we are given two different reactions (Rxn I and Rxn II) involving an epoxide ring opening. The goal is to predict the major product formed after each reaction. #### Reaction Schemes: 1. **Rxn I:** - **Starting Material:** An epoxide. - **Reagents:** H⁺ (Acid) and H₂O (Water). - **Product:** Two possible products, both are diols (compounds containing two hydroxyl groups). - Possible products: - A diol with hydroxyl groups on adjacent carbons. - Another diol isomer with hydroxyl groups on adjacent carbons but in a different stereochemical configuration. 2. **Rxn II:** - **Starting Material:** An epoxide. - **Reagents:** NaOCH₃ (Sodium methoxide) followed by H₂O (Water). - **Product:** Two possible products, one is a methoxy alcohol and the other is a diol. - Possible products: - A methoxy alcohol with the hydroxyl and methoxy groups on adjacent carbons. - A diol with hydroxyl groups on adjacent carbons but with different stereochemistry. #### Reaction Conditions: - **Rxn I:** Takes place under acidic conditions which typically leads to ring opening at the more substituted carbon due to protonation of the epoxide. - **Rxn II:** Takes place under basic conditions involving NaOCH₃, resulting in nucleophilic attack at the less substituted carbon of the epoxide, followed by protonation with water. #### Answer Choices: The given products for each reaction are categorized from A to D to match the configurations detailed above. Each answer choice lists possible products for both Rxn I and Rxn II. **Answer Choices:** - **A:** - Rxn I: HO-CH₂-CH₂-OH - Rxn II: HO-CH₂-CH(OCH₃)-CH₃ - **B:** - Rxn I: (Two stereoisomers, hydroxyl groups in different configurations) - Rxn II: (Two stereoisomers involving CH₃O group instead of one hydroxyl group) - **C:** - Similar to answer choice A but with variations in stereochemistry for Rxn II products.
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