Alcohols Phenols and Ethers Test

Result

Alcohols Phenols and Ethers Test - 44

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

Trans - cyclohexane -1,2- diol can be obtained by the reaction of cyclohexene with :

A
$$KMnO_4$$

B
$$OsO_4$$

C
peroxy formic acid /$$ H_3 O^+$$

D
$$SeO_2$$

Solution

As shown in the above image peroxy formic acid results in the formation of trans diols.
Question 2
1 / -0

Based on above isomers answer the following.
Which isomers on dehydration with conc. $$H_2SO_4$$ give alkene which is capable to show geometrical isomerism?

A
g, h, f

B
b, d, a

C
a, b, c.

D
None of these

Solution

(a) (Refer to Image 1)
Shows geometrical isomers.
(b) (Refer to Image 2)
More stable alkene,
Shows geometrical isomers.
(c) (Refer to Image 3)
Will show geometrical isomer.
Question 3
1 / -0

Product $$(X)$$ of this reaction is:

A

B

C

D

Solution

Benzaldehyde acts as a protecting group.
Question 4
1 / -0

Based on above isomers answer the following.
Which isomer on dehydration with conc. $$H_3PO_4$$ undergo maximum rearrangement?

A
a

B
c

C
e

D
b

Solution

Rearrangement keeps occurring until the carbocation formed is stable.
Stability order $$3^o>2^o>1^o$$
Hence, option $$C$$ is correct.
Question 5
1 / -0

Reaction of $$R-2-$$butanol with $$p-$$toluenesulphonyl chloride in pyridine followed by reaction with $$LiBr$$ gives:

A
$$R-1-$$butyl bromide

B
$$R-2-$$butyl tosylare

C
$$R-1-$$butyl tosylate

D
$$R-2-$$butyl bromide

Solution

$$R-2$$ $$- butylbromide$$
The above reaction mechanism follows $$S_N1$$ mechanism.
$$-O-pTs$$ is a good leaving group thus a carbocation formed, which gives the product in same stereochemistry as of Reactant.
Question 6
1 / -0

Product of the reaction is :

A

B

C

D

Solution

$$H$$ and $$OH$$ added are in a cis configuration. Since this is syn hydration, it follows Anti-Markovnikov's Rule.
Question 7
1 / -0

Final product $$A$$ is:

A

B
$$CH_{2} = C = CH_{2}$$

C

D

Solution

Refer to Image
This is pinacol reaction. This reaction occurs in presence of Conc. $$H_2SO_4$$ (acidic medium). Adjacent diols under goes this reaction.
Question 8
1 / -0

Propene $$CH_{3} - CH = CH_{2}$$ can be converted into $$1$$-propanol by oxidation. Indicate which sets of reagents amongst the following is ideal to effect the above conversion?

A
$$KMnO_{4}$$ (alkaline)

B
Osmimum tetroxide $$(OsO_{4}/CH_{2}Cl_{2})$$

C
$$B_{2} H_{6}$$ and alk $$H_{2}O_{2}$$

D
$$O_{3}$$ and $$Zn/H_{2}O$$

Solution

$$CH_3-CH=CH_2\xrightarrow[]{B_2H_6}CH_3-\underset{H}{\underset{|}{C}}H-\underset{BH_2}{\underset{|}{C}H_2}\xrightarrow[]{H_2O_2} CH_3-CH_2-CH_2OH$$
This reaction is called as hydroboration-oxidation.
Question 9
1 / -0

Select the best method for the preparation of the following compounds :

A
reaction of cyclohexanone with $$CH_{3}Li$$

B
reaction of $$1-$$methylcyclohexene with $$Hg(OAc)_{2}$$ followed by $$NaBH_{4}$$

C
reaction of cyclohexene with $$BH_{4} ; NaOH/H_{2}O_{2}$$, followed by $$CH_{3}Br$$

D
reaction of cyclohexene with $$MCPBA$$, followed by $$CH_{ 3 }MgBr$$

Solution

$$MCPBA$$ (Meta-chloro perbenzoic acid) is used as an oxidizing agent to produce epoxides. Grignard reagents are used to produce alcohols from epoxides.
Question 10
1 / -0

$$CH_3-CH_2-CH_2-CH_2-
\overset{CH_3}{\overset{|}{\underset{CH_3}{\underset{|}{C}}}}-CH_2-CH_2-OH\xrightarrow[\Delta]{H^+}\underset{(major)}{(A)}$$
Product (A) is:

A
$$CH_3-CH_2-CH_2-CH_2-\underset{CH_3}{\underset{|}{C}}=CH-CH_3$$

B
$$CH_3-(CH_2)_3-C(CH_3)=C(CH_3)_2$$

C
$$CH_3-CH_2-CH_2-CH_2-\underset{CH_3}{\underset{|}{C}}=CH_2$$

D
$$CH_3-CH_2-\underset{CH_3}{\underset{|}{CH}}-CH_2-\overset{CH_3}{\overset{|}{C}}=CH_2$$

Solution

Carbocation rearrangement in acidic medium takes as shown

refer to image

order of stability of carbocation – teritiary>secondary>primary
More substituted alkene will formed as major product.
Option B is correct.