Home
Class 12
CHEMISTRY
(A) tert-Butyl methyl ether on cleavage ...

(A) tert-Butyl methyl ether on cleavage with HI at 373K gives tert-butyl iodide and methanol.
(R ) The reaction occurs by `S_(N^(2))` mechanism.

A

If both Assertion and Reason are true and Reason is correct explanation of Assertion.

B

If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.

C

If Assertion is true but Reason is false.

D

If both Assertion and Reason and false.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given question step by step, we need to analyze the reaction of tert-butyl methyl ether with HI and determine the mechanism involved. Here’s a structured breakdown of the solution: ### Step 1: Understand the Reaction The reaction involves tert-butyl methyl ether reacting with hydroiodic acid (HI). The expected products are tert-butyl iodide and methanol. ### Step 2: Write the Structure of tert-Butyl Methyl Ether Tert-butyl methyl ether can be represented as: \[ \text{(CH}_3)_3\text{C-O-CH}_3 \] This structure indicates that the ether has a tert-butyl group (three methyl groups attached to a carbon) and a methyl group attached to an oxygen atom. ### Step 3: Reaction with HI When tert-butyl methyl ether reacts with HI, the oxygen atom in the ether will be protonated by the hydrogen ion (H⁺) from HI. This leads to the formation of a positively charged oxonium ion: \[ \text{(CH}_3)_3\text{C-OH}_2^+ \] ### Step 4: Cleavage of the Ether The oxonium ion can undergo cleavage. The bond between the oxygen and the tert-butyl group can break, leading to the formation of a tert-butyl carbocation and methanol: \[ \text{(CH}_3)_3\text{C}^+ + \text{CH}_3\text{OH} \] ### Step 5: Nucleophilic Attack The iodide ion (I⁻) from HI can then attack the tert-butyl carbocation to form tert-butyl iodide: \[ \text{(CH}_3)_3\text{C}^+ + \text{I}^- \rightarrow \text{(CH}_3)_3\text{C-I} \] ### Step 6: Conclusion on Mechanism The formation of a carbocation intermediate indicates that the mechanism is not SN2 (which involves a direct attack and simultaneous bond breaking) but rather SN1, where the formation of a stable carbocation is a key step. ### Final Answer - **Assertion:** True (tert-butyl methyl ether gives tert-butyl iodide and methanol). - **Reason:** False (the reaction occurs by SN1 mechanism, not SN2).
Doubtnut Promotions Banner Mobile Dark
|

Similar Questions

Explore conceptually related problems

Assertion : Tert- butyl methyl ether on cleavage with HI at 373 K gives tert-bytyl iodide and methano. Reason : The reaction occurs by S_(N^(1)) mechanism.

Statement-I: Nucleophilic substitution reaction on an optically active alkyl halide gives a mixture of enantiomers. Because Statement-II: The reaction occurs by S_(N^(1)) mechanism.

Knowledge Check

  • (Z)-2-Butene reacts with Br_(2)//H_(2)O . The resulting bromohydrin when treated with methoxide in methanol undergoes an intramolecular S_(N^2) reaction. Taking into consideration the stereochemical consequences of the reaction mechanism involved, choose the final product(s) of these transformations.

    A
    (I) only
    B
    (II) only
    C
    (III) only
    D
    Equal amounts of (I) and (II)

    • Similar Questions

    Explore conceptually related problems

    A : Diphenyl ether is prepared by Williamson synthesis . R : This reaction generally proceed by S_(N)1 mechanism .

    tert-Butylbromide reacts with aq. NaOH by S_(N)1 mechanism while n-butylbromide reacts by S_(N)2 mechanism. Why?

    Among the following reactions (s), which gives (give) tert-butyl benzene as the major product?

    Assertion (A) tert-butyl bromide undergoes Wurtz reaction to give 2,2,3,3-tetramethylbutane. Reason (R ) In wurtz reaction, alkyl halides react with sodium in dry ether to give hydrocarbon containing double the number of carbon atoms present in the halide

    Read the given passage and answer the questions number 1 to 5 that follow: The substitution reaction of alkyl halide mainly occurs by S_N 1 and S_N 2 mechanism. Whatever mechanism alkyl halides follow for the substitution reaction to occur, the polarity of the carbon halogen bond is responsible for these substitution reactions. The rate of S_N 1 reactions are governed by the stability of carbocation whereas for S_N 2 reactions steric factor is the deciding factor. If the starting material is a chiral compound, we may end up with an inverted product or racemic mixture depending upon the type of mechanism followed by alkyl halide. Cleavage of ethers with HI also governed by steric factor and stability of carbocation, which indicates that in organic chemistry, these two major factors help us in deciding the kind of product formed 1. Predict the stereochemistry of the product formed if an optically active alkyl halide undergoes substitution reaction by S_N 1 mechanism. 2. Name the instrument used for measuring the angle by which the plane polarised light is rotated. 3. Predict the major product formed when 2-Bromopentane reacts with alcoholic KOH. 4. Give one use of CHI_3 5. Write the structures of the products formed when anisole is treated with HI.

    A : CH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C)-O-CH_(3) on reaction with conc. Hl gives CH_(3) - underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C)-I and CH_(3)OH major product . R : This reaction proceed by S_(N)1 mechanism .

    Write the name of the product when tert.butyl methyl ether is heated with conc. H_(2)SO_(4) .

    Home
    Profile