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Question #44506

Difficulty: 8/10 | 🟢 Free

The Question

Consider the following multi-step reaction sequence:

Step 1: $\ce{2-methylbut-2-ene + HBr ->[R_2O_2, h\nu] A (Major)}$

Step 2: $\ce{A + t-BuOK ->[t-BuOH, \Delta] B (Major)}$

Step 3: $\ce{B ->[(i) Hg(OAc)_2, H_2O][(ii) NaBH_4, OH^-] C (Major)}$

Identify the major product C and its stereochemical nature.

Options

A.
Racemic 3-methylbutan-2-ol
B.
2-methylbutan-2-ol (Achiral)
C.
3-methylbutan-1-ol (Achiral)
D.
Racemic 2-methylbutan-1-ol

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

Peroxide Effect (Kharasch)|E1/E2 Solvent and Base Effects|Haloalkanes and Haloarenes

Why This Question Is Tricky

Common Mistakes

This problem tests the intersection of kinetic vs thermodynamic control and regioselectivity under strict steric constraints.

Students frequently fall into two traps: (1) Assuming E2 elimination always yields the thermodynamic Saytzeff product, ignoring the steric bulk of the tert-butoxide base which forces the kinetic Hoffman product. (2) Confusing Oxymercuration-Demercuration with acid-catalyzed hydration, incorrectly predicting a 1,2-hydride shift that would lead to a tertiary alcohol.

The bulky base strictly enforces the Hoffman pathway, and the mercurinium ion intermediate strictly prevents carbocation rearrangement, uniquely leading to the racemic secondary alcohol.

Quick Facts About This Question

Question Information

Subject	Chemistry
Chapter	Hydrocarbons - Class 11 Part 2
Concept	Peroxide Effect (Kharasch)
Difficulty	8
Cognitive Load	7
Target Solve Time	160 sec
Access	Free