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प्रश्न
Explain primary benzylic halide shows higher reactivity by SN1 mechanism than other primary alkyl halide.
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उत्तर
- SN1 reaction involves the formation of a carbocation intermediate. The benzylic carbocation intermediate formed are resonance stabilized, and hence SN1 mechanism is favoured.
- Resonance stabilization of benzylic carbocation can be represented as:
- Reactivity order of alkyl halides towards SN1 mechanism is 3° > 2° > 1° > CH3X. That is, SN1 mechanism is least favoured in primary alkyl halides.
- Benzylic carbocation formed is more stable than the primary carbocation; therefore, primary benzylic halide shows higher reactivity by SN1 mechanism than other primary alkyl halide.
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संबंधित प्रश्न
from the following pair would undergo SN2 faster from the other?
a. CH3CH2CH2I b. CH3CH2CH2Cl
Complete the following reaction giving major products.
\[\begin{array}{cc}\ce{CH3 - CH = CH3 ->[Red P/Br2] A ->[Ag2O/H2O]B}\\|\phantom{.........................}\\
\ce{OH\phantom{.......................}}\end{array}\]
Name the reagent used to bring about the following conversion.
Ethyl bromide to ethyl isocyanide
Name the reagent used to bring about the following conversion.
Chlorobenzene to biphenyl
Arrange the following in the increasing order of boiling points.
- 1-Bromopropane
- 2- Bromopropane
- 1- Bromobutane
- 1-Bromo-2-methylpropane
Convert the following:
2-Chloropropane to propan-1-ol
Convert the following:
tert-Butyl bromide to isobutyl bromide
Complete the following reaction sequence by writing the structural formulae of the organic compound 'A', 'B' and 'C'.
\[\ce{Isopropyl alcohol ->[\triangle][PBr3] A ->[][NH3 excess] B}\]
Observe the following and answer the question given below.
Comment on the bond length of C–X bond in it.
The following will react faster by SN1 mechanism
Major product of the following reaction is _______________
\[\ce{CH3-CH2-Mg-Br + NH3 ->?}\]
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Explain the factors affecting SN1 and SN2 mechanism.
What is dehydrohalogenation? State the rule for the formation of the preferred product of dehydrohalogenation.
Which of the following is least reactive towards SN1 reactions?
Nitroalkanes are obtained in laboratory from primary or secondary alkyl halides by the action of ______.
How many metameric ethers are represented by the molecular formula C4H10O?
What type of hybridisation is present in carbocation formed during the alkaline hydrolysis of 1- bromo-1- phenyl ethane?
Identify 'B' in the following reaction.
\[\ce{2-Bromobutane ->[KOH alc.][\Delta] A ->[HI] B}\]
Write the product formed when alkyl halide reacts with silver nitrite.
The compound that reacts the fastest with sodium methoxide is ______.
Complete the following reaction giving major product.
\[\begin{array}{cc}
\ce{CH3}\phantom{...............}\\
|\phantom{..................}\\
\ce{CH3 - C - CH2 - Cl->[Na/dry ether]A}\\
|\phantom{..................}\\
\ce{CH3}\phantom{...............}\\
\end{array}\]
Complete the following reaction giving major product.
\[\begin{array}{cc}
\ce{CH3}\phantom{...............}\\
|\phantom{..................}\\
\ce{CH3 - C - CH2 - Cl ->[Na/dry ether]A}\\
|\phantom{...................}\\
\ce{CH3}\phantom{.................}
\end{array}\]
Complete the following reaction giving major product.
\[\begin{array}{cc}
\ce{CH3}\phantom{................}\\
|\phantom{...................}\\
\ce{CH3 - C - CH2 - Cl->[Na/ dry ether]A}\\
|\phantom{...................}\\
\ce{CH3}\phantom{................}\\
\end{array}\]
Which among the following is NOT benzylic halide?
