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Question #44611

Difficulty: 8/10 | 🟢 Free

The Question

An alkyl halide, \ceCH3−C(CH3)2−CH(Br)−CH3\ce{CH3-C(CH3)2-CH(Br)-CH3} (3-bromo-2,2-dimethylbutane), is subjected to two distinct reaction conditions:

Condition I: \cet−BuOK\ce{t-BuOK} in \cet−BuOH\ce{t-BuOH} at 80∘C→80^\circ\text{C} \rightarrow Major Product P\mathbf{P} Condition II: \ceAgNO3\ce{AgNO3} in \ceEtOH\ce{EtOH} at 80∘C→80^\circ\text{C} \rightarrow Major Product Q\mathbf{Q}

Identify the major organic products P\mathbf{P} and Q\mathbf{Q}.

Options

  • A.

    P\mathbf{P} = 3,3-dimethyl-1-butene; Q\mathbf{Q} = 2,3-dimethyl-2-butene

  • B.

    P\mathbf{P} = 2,3-dimethyl-2-butene; Q\mathbf{Q} = 2-ethoxy-2,3-dimethylbutane

  • C.

    P\mathbf{P} = 3,3-dimethyl-1-butene; Q\mathbf{Q} = 2-ethoxy-2,3-dimethylbutane

  • D.

    P\mathbf{P} = 2,3-dimethyl-1-butene; Q\mathbf{Q} = 2,3-dimethyl-2-butene

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Mechanism_Trap

Don't get tricked by the process! Learn the mechanical traps used in competitive exam questions.

Concepts Behind This Question

C-X Bond Polarization and Polarizability|SN1 Carbocation Rearrangement|E1/E2 Solvent and Base Effects

Why This Question Is Tricky

Common Mistakes

This question tests the critical distinction between kinetic control via concerted elimination (E2) and thermodynamic control via carbocation intermediates (E1).

The 'Lethal Collision' occurs when students assume that steric hindrance in the substrate will force an SN1/E1 pathway even in the presence of a strong base (Condition I), erroneously predicting a rearranged product for P.

Conversely, in Condition II, students often overlook that elevated temperatures shift the post-rearrangement product distribution from SN1 (ether) to E1 (alkene), failing to account for the entropic driving force of elimination.

Quick Facts About This Question

Question Information

SubjectChemistry
ChapterHaloalkanes and Haloarenes - Class 12
ConceptC-X Bond Polarization and Polarizability
Difficulty8
Cognitive Load7
Target Solve Time160 sec
AccessFree