Complete the reaction :

When benzene or substituted benzene is treated with an acid chloride in the presence of anhydrous aluminium chloride, it affords the corresponding ketone. This reaction is known as Friedel-Crafts acylation reaction. Here, benzene or substituted benzene is treated with benzyl chloride in the presence of anhydrous aluminium chloride, that gives Benzophenone and hydrochloric acid. Here is the chemical reaction:

Cyclohexanone forms cynohydrin in good yield but 2 , 2 , 6 - trimethylcyclohexanone does not. Explain.

The formation of cyanohydrin follows a nucleophilic attack of cyanide ion at the carbonyl carbon of the ketone. Cyclohexanone forms cyanohydrin as it gives a good yield but in the case of 2 , 2 , 6 - trimethylcyclohexanone , due to steric hindrance produced by three methyl groups in the structure, it does not give proper yield. No reaction.

Give the chemical equation for the reaction CH 3 COOH with following: C 2 H 5 OH in the presence of H + .

Esterification: Carboxylic acids are esterified with alcohols or phenols in the presence of a mineral acid such as concentrated H 2 SO 4 or HCl gas as a catalyst. So, acetic anhydride reacts with ethanol, which gives ethyl ethanoate. Here is the chemical reaction: CH 3 COOH + C 2 H 5 OH ⇌ H + CH 3 COOC 2 H 5 + H 2 O .

Give the chemical equation for the reaction of CH 3 COOH with following: LiAlH 4

Carboxylic acids are reduced to primary alcohols by lithium aluminium hydride or with diborane. Diborane does not easily reduce with the following functional groups such as ester, nitro, halo, etc. Sodium borohydride does not reduce carboxyl group. So, here acetic acid on reacting with lithium aluminium hydride, which gives ethyl alcohol. Here is the chemical reaction: CH 3 COOH → LiAlH 4 CH 3 CH 2 OH .

Give the chemical equation for the reaction of CH 3 COOH with following : PCl 3

The hydroxyl group of carboxylic acids behaves like that of alcohols and is easily replaced by chlorine atoms on treating with PCl 5 , PCl 3 or SOCl 2 . Thionyl chloride ( SOCl 2 ) is preferred because the other two products are gaseous and escape the reaction mixture making the purification of the products easier. Now, When acetic acid is heated with phosphorus trichloride, acetyl chloride and phosphorus acid are obtained. Here is the chemical reaction: 3 CH 3 COOH + PCl 3 → 3 CH 3 COCl + H 3 PO 3 .

Complete the following reaction:

Nucleophiles such as ammonia and its derivatives ( H 2 N - Z ) add to the carbonyl group of aldehydes and ketones. This reaction is reversible and catalysed by an acid. The equilibrium favours the product formation because of rapid dehydration of the intermediate to form schiff base( > C = N - Z ). Here is the complete reaction:

Explain the mechanism of nucleophilic addition reactions of aldehydes and ketones.

A nucleophile attacks the electrophilic carbon atom of the polar carbonyl group from a direction approximately perpendicular to the plane of sp 2 hybridised orbitals of carbonyl carbon. The hybridisation of carbon changes from sp 2 to sp 3 in this process and a tetrahedral alkoxide intermediate is produced. This intermediate captures a proton from the reaction medium to give the electrically neutral product. The net result is the addition of Nu – and H + across the carbon-oxygen double bond.

E M B I B E

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 12 - Aldehydes, Ketones and Carboxylic Acids>Haryana Board-2019>Q 7

EASY

12th Haryana Board

IMPORTANT

Earn 100

Draw structure of cyclopropanone oxime.

Chapter-Wise 3D Chemistry Videos from Embibe Experts EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY

02 min 43 sec

Preparation of Aromatic Aldehyde

Aromatic aldehydes are organic compounds that contain the CHO group, and they are used as chemicals in the pharmaceutical and plastics industries. Let's stud...

05 min 48 sec

Oxidation of Alcohols

Alcohols are organic compounds that have one or more OH group attached to a single-bonded alkane. Watch this video to learn how they can be oxidised to give...

14 min 25 sec

Friedel-Crafts Acylation Reaction

Friedel-Crafts reaction is a coupling reaction named after the French chemist Charles Friedel and James Mason Crafts, an American chemist. Watch this video t...

Learn and Prepare for any exam you want !

|

|

|

|

|

|

|

|