Single Choice

What are $$A$$ and $$B$$ in the following sequence of reactions (i) $$C{ H }_{ 3 }C{ H }_{ 2 }COOH\overset { P }{ \underset { { Br }_{ 2 } }{ \longrightarrow } } A$$ ; (ii) $$A \overset { (i) Alc\cdot KOH excess }{ \underset { (ii){ H }^{ + } }{ \longrightarrow } } B$$

A$$\begin{matrix} C{ H }_{ 3 }-CH\cdot COOH \\ | \\ Br \end{matrix},C{ H }_{ 2 }=CHCOOH$$
Correct Answer
B$$C{ H }_{ 3 }C{ H }_{ 2 }COBr,C{ H }_{ 2 }=CHCOOH$$
C$$\begin{matrix} C{ H }_{ 2 }C{ H }_{ 2 }COOH \\ | \\ Br \end{matrix},C{ H }_{ 2 }=CH\cdot COOH$$
D$$\begin{matrix} & Br & \\ & | & \\ { H }_{ 3 }C- & -- & -COOH \\ & | & \\ & Br & \end{matrix},\begin{matrix} { H }_{ 2 }C=C-COOH \\ | \\ Br \end{matrix}$$

Solution

$$A$$ and $$B$$ are $$\begin{matrix} C{ H }_{ 3 }-CH\cdot COOH \\ | \\ Br \end{matrix}$$ and $$C{ H }_{ 2 }=CHCOOH$$ respectively.

The sequence of reactions is as shown:
(i) Alpha hydrogen atom of propanoic acid is replaced with bromine.

$$C{ H }_{ 3 }C{ H }_{ 2 }COOH\overset { P }{ \underset { { Br }_{ 2 } }{ \longrightarrow } } \underset {A}{\begin{matrix} C{ H }_{ 3 }-CH\cdot COOH \\ | \\ Br \end{matrix}}$$

(ii) Bromine is replaced with $$-OH$$ group in alkaline hydrolysis in alcoholic medium. This is followed by dehydration.

$$\underset {A} {\begin{matrix} C{ H }_{ 3 }-CH\cdot COOH \\ | \\ Br \end{matrix}} \overset { (i) Alc\cdot KOH excess }{ \underset {
(ii){ H }^{ + } }{ \longrightarrow } } \underset {B}{C{ H }_{ 2 }=CHCOOH}$$

SIMILAR QUESTIONS

Physical World

In the presence of a small amount of phosphorous, aliphatic carboxylic acids react with chlorine or bromine to yield a compound in which $$\alpha$$-hydrogen has been replaced by halogen. This reaction is known as:

Physical World

$$CH_{3}CH_{2}COOH \xrightarrow[Fe]{Cl_{2}} X\xrightarrow[KOH]{alc.}Y$$ The compound $$Y$$ is :

Physical World

The following acids can be differentiated by:

Physical World

The reaction $$CH_3COOH+Cl_2\overset{P}{\rightarrow}ClCH_2COOH+HCl$$ is called :

Physical World

Hell-Volhard -Zelinsky reaction involves the replacement of an ------ atom from from the alkyl group of a monocarboxylic acid by a ------ atom.

Physical World

The reaction of chlorine on carboxylic acids to form alpha chloro acids is called as:

Physical World

State whether the following statement is True or False: HEll-Volhard-Zelinsky reaction is given by those acids which have $$\alpha$$ hydrogen atoms

Physical World

Which of the following will not undergo HVZ reaction?

Physical World

$${CH}_{3}{CH}_{2}COOH\xrightarrow [ Red\quad P ]{ { Cl }_{ 2 } } (A)\xrightarrow [ ]{ Alc.KOH } (B)$$ The compound (B) is:

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