Advertisements
Advertisements
प्रश्न
Explain why nucleophilic substitution reactions are not very common in phenols.
Advertisements
उत्तर
The C – O bond in phenols has some double-bond character due to resonance and hence cannot be easily cleaved by nucleophiles. So, nucleophilic substitution reactions are not very common in phenols and they give many electrophilic substitution reactions.
APPEARS IN
संबंधित प्रश्न
Show how will you synthesize pentan-1-ol using a suitable alkyl halide.
Give the equation of the following reaction:
Oxidation of propan-1-ol with alkaline KMnO4 solution.
Write the mechanism of acid-catalysed dehydration of ethanol to yield ethene.
When 3-methylbutan-2-ol is treated with HBr, the following reaction takes place:
\[\begin{array}{cc}
\phantom{.......................}\ce{Br}\\
\phantom{......................}|\\
\ce{CH3 - CH - CH - CH3 ->[HBr] CH3 - C - CH2 - CH3}\\
\phantom{.}|\phantom{......}|\phantom{......................}|\phantom{........}\\
\phantom{}\ce{CH3}\phantom{...}\ce{OH}\phantom{...................}\ce{CH3}\phantom{.....}
\end{array}\]
Give a mechanism for this reaction.
(Hint: The secondary carbocation formed in step II rearranges to a more
stable tertiary carbocation by a hydride ion shift from 3rd carbon atom.)
In the reduction \[\ce{R - CHO + H2 -> RCH2OH}\] the catalyst used is:
Which of the following are used to convert RCHO into RCH2OH?
(i) H2/Pd
(ii) LiAlH4
(iii) NaBH4
(iv) Reaction with RMgX followed by hydrolysis
Primary and secondary alcohols on the action of reduced copper give:
\[\ce{CH3CH2OH}\] can be converted into \[\ce{CH3CHO}\] by ______.
Identify the secondary alcohols from the following set:
- \[\ce{CH3CH2CH(OH)CH3}\]
- \[\ce{(C2H5)3COH}\]
Explain why is OH group in phenols more strongly held as compared to OH group in alcohols.
Why is the C – O – H bond angle in alcohols slightly less than the tetrahedral angle whereas the C – O – C bond angle in ether is slightly greater?
What is Lucas reagent?
The correct geometry around oxygen in CH3OCH3 is
Which of the following alcohols will not undergo oxidation?
Write the mechanism of acid dehydration of ethanol to yield ethene.
Write the mechanism of acid-catalysed dehydration of ethanol to yield ethene.
Write the mechanism of acid dehydration of ethanol to yield ethene.
Write the mechanism of acid-catalysed dehydration of ethanol to yield ethene
