Claisen Condensation

Q. Acetaldehyde when treated with dilute NaOH gives

1. $$C{H}_{3}C{H}_{2}OH$$

2. $$C{H}_{3}COOH$$

3. $$C{H}_3-\underset{\underset{OH}{|}}{CH}-C{H}_2-CHO$$

4. $$C{H}_3-C{H}_3$$

Q.

Self-condensation of two moles of ethyl acetate in presence of Sodium ethoxide yields:

1. ethyl butyrate

2. acetoacetic ester

3. ethyl propionate

4. methyl acetoacetate

Q. Aniline on reaction with acetyl chloride in the presence of NaOH gives :

1. Phenol
2. acetamide
3. acetanilide
4. Benzene

Q. On treating ethanal with dil.NAOH, What is the product?

Q.

Give plausible explanation for each of the following:

(i) Cyclohexanone forms cyanohydrin in good yield but 2, 2, 6 trimethylcyclohexanone does not.

(ii) There are two −NH₂ groups in semicarbazide. However, only one is involved in the formation of semicarbazones.

(iii) During the preparation of esters from a carboxylic acid and an alcohol in the presence of an acid catalyst, the water or the ester should be removed as soon as it is formed.

Q. acetic acid undergoes dimerisation in benzene. what will be its vant hoff factor if its alpha is 8%

Q.

What is the product formed when N, N-dimethyl acetamide is reduced?

1. Ethyl dimethylamine

2. Chloromethane

3. Ethyl methylamine

4. Benzylamine

Q. $C_6{H}_6+C_6{H}_{5}Cl\stackrel{anhyd.AlC{l}_3}{\to }P.$
In the above reaction, product $P$ is:

1. 
2. 
3. 
4. No reaction

Q. Benzaldehyde reacts with X to produce cinnamaldehyde in Claisen condensation. X is :

1. formaldehyde
2. acetaldehyde
3. crotonaldehyde
4. propanaldehyde

Q. The reaction
$C_6{H}_{5}CHO+C{H}_{3}CHO\to C_6{H}_{5}CH=CH-CHO$
is known as

1. Perkin's reaction

2. Benzoin condensation

3. Claisen condensation

4. Cannizzaro's reaction

Q. The number of P-O-P linkages in cylic metaphosphoric acid is

1. zero
2. two
3. four.
4. three

Q. The reagent with which both acetaldehyde and acetone react easily is

1. Fehling's solution
2. Grignard reagent
3. Schiff's reagent
4. Tollen's reagent

Q. What is true about the following Claisen condensation reaction?

1. The reaction proceeds through a carbanion intermediate.
2. If ethyl propanoate is taken in place of ethyl acetate, condensation would occur at faster rate.
3. The condensation reaction could also be carried out in presence of acid catalyst.
4. All of the above.

Q.

Draw formulas for the first five members of each homologous series beginning with the following compounds. (a) H–COOH (b) CH₃COCH₃ (c) H–CH=CH₂

Q. Which of the following cannot undergo $E2$ reaction?

1. 
2. 
3. 
4. 

Q. Which of the following can be used for 1, 2, 3, 4, 5, 6 -hexachlorocyclohexane?

1. Lindane
2. Gammexane
3. 666
4. HCB

Q.

Write structural formulas and names of four possible aldol condensation products from propanal and butanal. In each case, indicate which aldehyde acts as nucleophile and which as electrophile.

Q. The following reaction is known by the name :

1. Coupling reaction
2. Schotten-Baumen reaction
3. Friedel-Craft's reaction
4. Carbylamine reaction

Q. 15. Acetic acid undergoes dimerisation in benzene. What will be its vant Hoff factor valure if α is 100%?

Q.

Acetoacetic ester is made by the process of:

1. esterification

2. condensation

3. polymerisation

4. isomerisation

Q. Benzaldehyde reacts with X to produce cinnamaldehyde in Claisen condensation. X is :

1. formaldehyde
2. acetaldehyde
3. crotonaldehyde
4. propanaldehyde

Q. Write the structural formula of i) 3-oxopentanal ii) pent-2-enal
iii) 4-methylpent-3-en-2-one. iv) Hex-2-en-4-ynoic acid
v) 4-methylpent-3-en-2-one vi) 3-hydroxybutanal vii) 2-phenylethanoic acid.

Q.

Self-condensation of two moles of ethyl acetate in presence of Sodium ethoxide yields:

1. ethyl propionate

2. ethyl butyrate

3. acetoacetic ester

4. methyl acetoacetate

Q. When phenyl magnesium bromide reacts with isopropyl bromide, n-propyl benzene is obtained.

1. True
2. False

Q.

Acetoacetic ester is made by the process of:

1. esterification

2. condensation

3. polymerisation

4. isomerisation

Q. The reaction
$C_6{H}_{5}CHO+C{H}_{3}CHO\to C_6{H}_{5}CH=CH-CHO$
is known as

1. Perkin's reaction

2. Claisen condensation

3. Benzoin condensation
4. Cannizzaro's reaction

Q. Benzaldehyde reacts with X to produce cinnamaldehyde in Claisen condensation. X is :

1. formaldehyde
2. acetaldehyde
3. crotonaldehyde
4. propanaldehyde

Q. The following reaction is known by the name :

1. Coupling reaction
2. Schotten-Baumen reaction
3. Friedel-Craft's reaction
4. Carbylamine reaction

Q. In which of the following reaction cyanide will be obtained as a major product?

1. $Ph-\stackrel{O}{\stackrel{||}{C}}-C{H}_3\stackrel{\left(i\right)LiAl{H}_4}{\underset{\left(ii\right)H_3{O}^{+}}{\to }}$
2. $Ph-\stackrel{O}{\stackrel{||}{C}}-N{H}_2\stackrel{P_4{O}_{10}}{\to }$
3. $Ph-\stackrel{O}{\stackrel{||}{C}}-N{H}_2\stackrel{NaOH}{\underset{B{r}_2}{\to }}$
4. $Ph-\stackrel{O}{\stackrel{||}{C}}-O-H\stackrel{SOC{l}_2}{\to }\stackrel{N{H}_3}{\to }$

Q. The major product P in the following reaction is
${CH}_3-CH={CH}_2\underset{HI}{\overset{peroxide}{\to }}P$

1. ${CH}_3{CH}_2{CH}_{2}I$
2. ${CH}_2-\underset{\underset{I}{|}}{CH}-{CH}_3$
3. $\underset{\underset{I}{|}}{{CH}_2}-CH={CH}_2$
4. $\underset{\underset{I}{|}}{{CH}_2}-\underset{\underset{I}{|}}{{CH}_2}$