
a) Illustrate the following name reactions giving suitable example in each case:
i) Clemmensen reduction
ii) Hell-Volhard-Zelinsky reaction
b) How are the following conversions carried out?
(i) Ethyl cyanide to ethanoic acid
(ii) Butan-1-ol to butanoic acid
(iii)Benzoic acid to m-bromobenzoic acid
Answer
125.1k+ views
Hint: As we know clemmensen reduction is based on the reduction of ketones, or aldehydes, and the reaction Hell-Volhard-Zelinsky reaction is related to the alpha position addition in the carboxylic acid. If we talk about the conversions, then these conversions will be done with the help of bromine, or potassium permanganate.
Complete step by step answer:
Now, we will talk about all the reactions step by step.
First, we will discuss part (a).
The first (i) reaction is Clemmensen reduction.
As mentioned this reaction includes the reduction of aldehydes or ketones using hydrochloric acid, and zinc amalgam, and it is reduced to the alkanes. So, let us take an example of acetophenone.
The chemical reaction is

Here, we can see acetophenone is reduced to the Ethyl benzene, or 1-Phenyl Ethane
Now, the second (ii) reaction is Hell- Volhard-Zelinsky, it involves the halogenation of carboxylic acids at the alpha carbon position. This reaction is carried out with the catalytic amount of phosphorus tribromide, and the addition of diatomic bromine.
The chemical reaction is

Here we can see the general carboxylic addition forms alpha-bromo carboxylic acid.
Now, we will discuss the part (b).
The first (i) is the conversion of Ethyl cyanide to ethanoic acid.
The conversion will take place thru hydrolysis, then diatomic bromine, and potassium permanganate. The chemical reaction is

Now, the second (ii) is the conversion of butan -1- ol to butanoic acid. It is done by the use of potassium permanganate. The chemical reaction is

The third (iii) is the conversion of benzoic acid to m-bromobenzoic acid. It takes place through the bromination of benzoic acid. The chemical reaction is
Now, in the end we can conclude that in part (a) (i) the product is alkane, and in (ii) the product is alpha – bromo carboxylic acid. In the part (b) we have shown the conversion reactions.
Note: It is important to know that in the Hell-Volhard- Zelinsky reaction, there is no fluorination, and iodination of carboxylic acids. So, we just consider the bromination of carboxylic acids.
Complete step by step answer:
Now, we will talk about all the reactions step by step.
First, we will discuss part (a).
The first (i) reaction is Clemmensen reduction.
As mentioned this reaction includes the reduction of aldehydes or ketones using hydrochloric acid, and zinc amalgam, and it is reduced to the alkanes. So, let us take an example of acetophenone.
The chemical reaction is

Here, we can see acetophenone is reduced to the Ethyl benzene, or 1-Phenyl Ethane
Now, the second (ii) reaction is Hell- Volhard-Zelinsky, it involves the halogenation of carboxylic acids at the alpha carbon position. This reaction is carried out with the catalytic amount of phosphorus tribromide, and the addition of diatomic bromine.
The chemical reaction is

Here we can see the general carboxylic addition forms alpha-bromo carboxylic acid.
Now, we will discuss the part (b).
The first (i) is the conversion of Ethyl cyanide to ethanoic acid.
The conversion will take place thru hydrolysis, then diatomic bromine, and potassium permanganate. The chemical reaction is

Now, the second (ii) is the conversion of butan -1- ol to butanoic acid. It is done by the use of potassium permanganate. The chemical reaction is

The third (iii) is the conversion of benzoic acid to m-bromobenzoic acid. It takes place through the bromination of benzoic acid. The chemical reaction is

Now, in the end we can conclude that in part (a) (i) the product is alkane, and in (ii) the product is alpha – bromo carboxylic acid. In the part (b) we have shown the conversion reactions.
Note: It is important to know that in the Hell-Volhard- Zelinsky reaction, there is no fluorination, and iodination of carboxylic acids. So, we just consider the bromination of carboxylic acids.
Recently Updated Pages
JEE Main 2021 July 20 Shift 2 Question Paper with Answer Key

JEE Atomic Structure and Chemical Bonding important Concepts and Tips

JEE Amino Acids and Peptides Important Concepts and Tips for Exam Preparation

JEE Main 2023 (January 30th Shift 2) Maths Question Paper with Answer Key

JEE Main 2022 (July 25th Shift 2) Physics Question Paper with Answer Key

Classification of Elements and Periodicity in Properties Chapter For JEE Main Chemistry

Trending doubts
JEE Main 2025 Session 2: Application Form (Out), Exam Dates (Released), Eligibility & More

JEE Main Exam Marking Scheme: Detailed Breakdown of Marks and Negative Marking

JEE Main 2023 January 24 Shift 2 Question Paper with Answer Keys & Solutions

Learn About Angle Of Deviation In Prism: JEE Main Physics 2025

JEE Main 2025: Conversion of Galvanometer Into Ammeter And Voltmeter in Physics

JEE Main Login 2045: Step-by-Step Instructions and Details

Other Pages
NCERT Solutions for Class 12 Chemistry Chapter 6 Haloalkanes and Haloarenes

JEE Advanced Marks vs Ranks 2025: Understanding Category-wise Qualifying Marks and Previous Year Cut-offs

NCERT Solutions for Class 12 Chemistry Chapter 1 Solutions

NCERT Solutions for Class 12 Chemistry Chapter 2 Electrochemistry

NCERT Solutions for Class 12 Chemistry Chapter 8 Aldehydes Ketones and Carboxylic Acids

NCERT Solutions for Class 12 Chemistry Chapter 9 Amines
