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प्रश्न
Identify 'A' in the following reaction -
(a) 2- Bromo-2 methylbutane
(b) 1 -Bromo-2,2-dimethylpropane
(c) 1 - Bromo - 3 -methylbutane
(d) 1 - Bromo- 2 -methylpropane
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उत्तर
1 -Bromo-2,2-dimethylpropane
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संबंधित प्रश्न
Write the major products(s) in the following:
Give reasons for the following:
(CH3)3C–O–CH3 on reaction with HI gives (CH3)3C–I and CH3–OH as the main products and not (CH3)3C–OH and CH3–I.
Write the structure of the major product in each of the following reaction :
How will you bring about the following conversion?
Toluene to benzyl alcohol
Write the structure of the major organic product in the following reaction:
\[\ce{CH3CH2CH2OH + SOCl2 ->}\]
Given reasons: SN1 reactions are accompanied by racemization in optically active alkyl halides.
Which would undergo SN2 reaction faster in the following pair and why ?
CH3 – CH2 – Br and CH3 – CH2 – I
What is the action of the following on ethyl bromide?
silver acetate
Which of the following is a primary halide?
SN2 mechanism proceeds through intervention of ____________.
Tertiary alkyl halides are practically inert to substitution by SN2 mechanism because of ____________.
Which of the following is the correct order of decreasing SN2 reactivity?
Which of the following is an optically active compound?
The process of separation of a racemic modification into d and l-enantiomers is called ____________.
2-Bromopentane is heated with potassium ethoxide in ethanol. The major product obtained is ____________.
SN1 reaction of alkyl halides lead to ___________.
Identify X and Y in the following sequence:
\[\ce{C2H5Br ->[X] Product ->[Y] C3H7NH2}\]
Assertion: KCN reacts with methyl chloride to give methyl isocyanide.
Reason: CN– is an ambident nucleophile.
A primary alkyl halide would prefer to undergo ______.
Which of the compounds will react faster in SN1 reaction with the –OH ion?
\[\ce{CH3-CH2-Cl}\] or \[\ce{C6H5-CH2-Cl}\]
Write the structures and names of the compounds formed when compound ‘A’ with molecular formula, \[\ce{C7H8}\] is treated with \[\ce{Cl2}\] in the presence of \[\ce{FeCl3}\].
Which one of the following compounds is more reactive towards SN1 reaction?
The decreasing order of reactivity of the following compounds towards nucleophilic substitution (SN2) is ______.
Arrange the following compounds in increasing order of reactivity towards SN2 reaction.
2-Bromopentane, 1-Bromopentane, 2-Bromo-2-methylbutane
The following questions are case-based questions. Read the passage carefully and answer the questions that follow:
|
Nucleophilic Substitution: Influences of solvent polarity: The reaction rate (SN2) of 2-bromopropane and NaOH in ethanol containing 40% water is twice slower than in absolute ethanol. Hence the level of solvent polarity has an influence on both SN1 and SN2 reactions but with different results. Generally speaking, a weak polar solvent is favourable for SN2 reaction, while a strong polar solvent is favourable for SN1. Generally speaking, the substitution reaction of tertiary haloalkane is based on SN1 mechanism in solvents with a strong polarity (for example ethanol containing water). |
Answer the following questions:
(a) Why racemisation occurs in SN1? (1)
(b) Why is ethanol less polar than water? (1)
(c) Which one of, the following in each pair is more reactive towards SN2 reaction? (2)
(i) CH3 – CH2 – I or CH3CH2 – Cl
(ii)
OR
(c) Arrange the following in the increasing order of their reactivity towards SN1 reactions: (2)
(i) 2-Bromo-2-methylbutane, 1-Bromo-pentane, 2-Bromo-pentane
(ii) 1-Bromo-3-methylbutane, 2-Bromo-2-methylbutane, 2-Bromo-3- methylbutane
An organic compound A with the molecular formula (+) C4H9Br undergoes hydrolysis to form (+) C4H9OH. Give the structure of A and write the mechanism of the reaction.
Which alkyl halide from the following pair would you expect to react more rapidly by an SN2 mechanism? Explain your answer.
\[\begin{array}{cc}\ce{CH3CHCH2CH2Br}\\|\phantom{.........}\\\ce{CH3}\phantom{......}\end{array}\] or \[\begin{array}{cc}\ce{CH3CH2CHCH2Br}\\\phantom{}|\\\phantom{...}\ce{CH3}\end{array}\]
