Learn
Games

8.9.3.1 - Reduction

Interactive Audio Lesson

Listen to a student-teacher conversation explaining the topic in a relatable way.

Introduction to Reduction

Unlock Audio Lesson

Signup and Enroll to the course for listening the Audio Lesson

Teacher
Teacher

Today, we’re going to talk about the reduction of carboxylic acids. Reduction is a chemical reaction that involves the gain of electrons or hydrogen, resulting in the decrease of oxidation state.

Student 1
Student 1

So, what does it mean to reduce a carboxylic acid?

Teacher
Teacher

Great question! When we reduce a carboxylic acid, we are converting it into a primary alcohol. For example, R-COOH can be reduced to R-CHOH.

Student 2
Student 2

What reagents do we use for this reduction?

Teacher
Teacher

The primary reagents are lithium aluminium hydride and diborane. Remember, we can use the acronym LiAlH4 for lithium aluminium hydride!

Student 3
Student 3

What about sodium borohydride?

Teacher
Teacher

Good point! Sodium borohydride can't reduce carboxylic acids; it’s used for milder reductions, mostly aldehydes and ketones.

Student 4
Student 4

So, we need specific conditions to reduce carboxylic acids effectively?

Teacher
Teacher

Exactly! Each reagent has its specific characteristics that affect the reaction they can undergo. Let’s remember, LiAlH4 is very reactive and can reduce a wide range of groups.

Teacher
Teacher

Now, let’s summarize: reducing carboxylic acids yields primary alcohols and relies primarily on LiAlH4 and diborane. Can anyone give examples of reactions that wouldn’t work with sodium borohydride?

Key Reagents in Reduction

Unlock Audio Lesson

Signup and Enroll to the course for listening the Audio Lesson

Teacher
Teacher

Let’s examine the main reagents further. What can anyone tell me about lithium aluminium hydride?

Student 1
Student 1

Isn't it a strong reducing agent?

Teacher
Teacher

Yes! It's highly reactive and capable of reducing various functional groups, including carboxylic acids. And what about diborane?

Student 2
Student 2

I remember it’s less versatile than LiAlH4, but still useful!

Teacher
Teacher

Right on! Diborane is selective; it doesn’t easily reduce functional groups like esters and nitro groups, making it safer for some reactions.

Student 3
Student 3

Could that be an advantage for specific reductions?

Teacher
Teacher

Absolutely! Understanding the limitations helps us choose the right reagent for desired outcomes. What are some reactions we could avoid with diborane?

Student 4
Student 4

Reactions involving esters or nitro compounds, for instance.

Teacher
Teacher

Good summary! To wrap up, when approaching reductions, we must understand our reagents and their implications.

Introduction & Overview

Read a summary of the section's main ideas. Choose from Basic, Medium, or Detailed.

Quick Overview

Carboxylic acids can be converted to primary alcohols through reduction using specific reagents like lithium aluminium hydride and diborane.

Standard

This section discusses the reduction of carboxylic acids to primary alcohols using lithium aluminium hydride (LiAlH4) and diborane (B2H6). It highlights that while diborane is effective for this conversion, it is less likely to reduce other functional groups, such as esters, nitro groups, and halogens. It also mentions that sodium borohydride (NaBH4) is not suitable for reducing carboxyl groups.

Detailed

Reduction of Carboxylic Acids

In organic chemistry, the reduction of carboxylic acids (R-COOH) to primary alcohols (R-CHOH) is a crucial transformation. The process can be effectively achieved using lithium aluminium hydride (LiAlH4) and diborane (B2H6).

Key Reagents

  • Lithium Aluminium Hydride (LiAlH4): A strong reducing agent commonly used in reduction reactions. It is capable of reducing a wide range of functional groups, including carboxylic acids.
  • Diborane (B2H6): This reagent is also effective in reducing carboxylic acids but has limitations in reducing functional groups such as esters, nitro compounds, and halides.
  • Sodium Borohydride (NaBH4): It's important to note that NaBH4 does not reduce carboxylic acids; it is milder and mainly used for the reduction of aldehydes and ketones.

Summary of Reaction

The general equation representing this reduction is:
R-COOH + (i) LiAlH4 or B2H6 → R-CHOH
This transformation is significant in organic synthesis, allowing the modification of carboxylic acids into alcohols, which are versatile intermediates in various chemical processes.

Youtube Videos

Reduction of Aldehydes and Ketones - Aldehydes, Ketones & Carboxylic Acids | Class 12 Chemistry Ch 8
Reduction of Aldehydes and Ketones - Aldehydes, Ketones & Carboxylic Acids | Class 12 Chemistry Ch 8
Aldehydes Ketones and Carboxylic Acid FULL CHAPTER | Class 12th Organic Chemistry | PhysicsWallah
Aldehydes Ketones and Carboxylic Acid FULL CHAPTER | Class 12th Organic Chemistry | PhysicsWallah
Aldehydes, Ketones & Carboxylic Acids - One Shot Revision | Class 12 Chemistry Chapter 8 | CBSE 2024
Aldehydes, Ketones & Carboxylic Acids - One Shot Revision | Class 12 Chemistry Chapter 8 | CBSE 2024
Aldehydes,Ketones & Carboxylic Acids Class 12 Chemistry Chapter 8 One Shot | New NCERT CBSE
Aldehydes,Ketones & Carboxylic Acids Class 12 Chemistry Chapter 8 One Shot | New NCERT CBSE
#Aldehyde ketone carboxylic acid *1#
#Aldehyde ketone carboxylic acid *1#
Plus Two Chemistry - Mark Room - Aldehydes , Ketones and Carboxylic Acids | Xylem Plus Two
Plus Two Chemistry - Mark Room - Aldehydes , Ketones and Carboxylic Acids | Xylem Plus Two
Aldehydes Ketones and Carboxylic acids One Shot | Class12 Chemistry Chapter 12 | CBSE JEE NEET
Aldehydes Ketones and Carboxylic acids One Shot | Class12 Chemistry Chapter 12 | CBSE JEE NEET
class 12 Aldehyde ketones and carboxylic acid (part 7)
class 12 Aldehyde ketones and carboxylic acid (part 7)
Preparation of Aldehyde and Ketone (Part 2) | Class 12 Chemistry Chapter 8 | CBSE 2024-25
Preparation of Aldehyde and Ketone (Part 2) | Class 12 Chemistry Chapter 8 | CBSE 2024-25
12. ALDEHYDES KETONES AND CARBOXYLIC ACIDS | Lecture - 4 | Eklavya 5.0 | Class 12 Chemistry #mhtcet
12. ALDEHYDES KETONES AND CARBOXYLIC ACIDS | Lecture - 4 | Eklavya 5.0 | Class 12 Chemistry #mhtcet

Audio Book

Dive deep into the subject with an immersive audiobook experience.

Reducing Carboxylic Acids to Primary Alcohols

Unlock Audio Book

Signup and Enroll to the course for listening the Audio Book

Carboxylic acids are reduced to primary alcohols by lithium aluminium hydride or better with diborane.

Detailed Explanation

Carboxylic acids, a type of organic compound, can be turned into primary alcohols through a chemical process called reduction. In this process, specific reagents like lithium aluminium hydride (LiAlH4) or diborane (B2H6) are used. Lithium aluminium hydride is a strong reducing agent that can effectively convert carboxylic acids to primary alcohols by introducing hydrogen into the carboxylic acid structure. Diborane is pointed out as a better option because it can reduce carboxylic acids while being less reactive towards other functional groups, making the reaction more selective.

Examples & Analogies

Think about making a smoothie. You have a fruit (the carboxylic acid) that you want to turn into a delicious drink (the primary alcohol). Using lithium aluminium hydride or diborane is like using a high-quality blender that effectively transforms your fruit into a smooth beverage without leaving chunks behind. Just as a blender makes the process easier and cleaner, these chemical reagents ensure a successful reduction.

Reactivity of Diborane

Unlock Audio Book

Signup and Enroll to the course for listening the Audio Book

Diborane does not easily reduce functional groups such as ester, nitro, halo, etc.

Detailed Explanation

While diborane is effective for reducing carboxylic acids to alcohols, it has limited reactivity with other functional groups. Functional groups such as esters, nitro groups, and haloalkanes are generally resistant to reduction by diborane. This means that when carrying out chemical reactions involving diborane, scientists must consider which other groups are present because they might remain unchanged during the reaction. This selectivity is useful for ensuring that only the targeted carboxylic acid is converted without affecting other parts of the molecule.

Examples & Analogies

Imagine diborane as a precision tool, like a laser cutter. A laser cutter can cut specific materials very precisely but might not work as effectively or at all on other materials. In our case, diborane can 'cut down' the carboxylic acids into alcohols but leaves the 'surrounding materials' (functional groups like esters or nitro groups) intact, allowing chemists to focus on transforming only what they want.

Sodium Borohydride Limitations

Unlock Audio Book

Signup and Enroll to the course for listening the Audio Book

Sodium borohydride does not reduce the carboxyl group.

Detailed Explanation

Sodium borohydride (NaBH4) is another reducing agent commonly used in organic chemistry. However, it is important to note that sodium borohydride does not have the ability to reduce the carboxyl group, which is a functional group found in carboxylic acids. Therefore, if you're trying to convert a carboxylic acid into a primary alcohol, sodium borohydride would not be an appropriate choice. This characteristic highlights the importance of selecting the right reducing agent based on the functional groups present in the compound you are working with.

Examples & Analogies

Think of sodium borohydride as a specialized kitchen appliance, like an apple peeler. While the apple peeler is great for peeling apples (similar to what sodium borohydride can reduce), it won't help you make apple juice from apples (the carboxyl group reduction). If you want to make juice, you’ll need a blender—just as you need a stronger reducing agent like lithium aluminium hydride or diborane to reduce the carboxyl group.

Definitions & Key Concepts

Learn essential terms and foundational ideas that form the basis of the topic.

Key Concepts

  • Lithium Aluminium Hydride (LiAlH4): A strong reducing agent used for the reduction of carboxylic acids to alcohols.

  • Diborane (B2H6): Effective in reducing carboxylic acids but does not reduce esters or nitro compounds.

  • Sodium Borohydride (NaBH4): Milder than LiAlH4; ineffective for carboxylic acids.

Examples & Real-Life Applications

See how the concepts apply in real-world scenarios to understand their practical implications.

Examples

  • The reduction of acetic acid (CH3COOH) to ethanol (CH3CH2OH) using lithium aluminium hydride.

  • Diborane reducing benzoic acid (C6H5COOH) to benzyl alcohol (C6H5CHOH).

Memory Aids

Use mnemonics, acronyms, or visual cues to help remember key information more easily.

🎵 Rhymes Time

  • Reducing bonds with LiAlH4, transforms acids to alcohols galore!

📖 Fascinating Stories

  • Imagine a busy chemist named LiAl who always managed to turn carboxylic acids into happy alcohols - that's the power of reduction with LiAlH4!

🧠 Other Memory Gems

  • Think 'Diboard game' - it can reduce carboxylic acids but not other players like esters or nitro compounds.

🎯 Super Acronyms

For LiAlH4, think 'Larva in Acid Leads to Hydrogen 4' to remember its reactivity and function!

Flash Cards

Review key concepts with flashcards.

Glossary of Terms

Review the Definitions for terms.

  • Term: Reduction

    Definition:

    A chemical reaction involving the gain of electrons or hydrogen, leading to a decrease in oxidation state.

  • Term: Carboxylic Acid

    Definition:

    An organic acid containing a carboxyl group (-COOH).

  • Term: Lithium Aluminium Hydride (LiAlH4)

    Definition:

    A strong reducing agent used to convert carboxylic acids to primary alcohols.

  • Term: Diborane (B2H6)

    Definition:

    A chemical compound effective in reducing carboxylic acids but not other functional groups like esters or nitro groups.

  • Term: Sodium Borohydride (NaBH4)

    Definition:

    A milder reducing agent that does not reduce carboxylic acids.