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Question #44493

Difficulty: 8/10 | 🟢 Free

The Question

Consider the following reaction sequence for 1-methylcyclohex-1-ene (Compound \textbf{A}): $\textbf{A} \xrightarrow[0^\circ\text{C}]{\text{BH}_3 \cdot \text{THF}} \textbf{B} \xrightarrow[\text{diglyme}]{\Delta, 160^\circ\text{C}} \textbf{C} \xrightarrow[\text{H}_2\text{O}]{\text{H}_2\text{O}_2, \text{NaOH}} \textbf{D}$ Identify the major product \textbf{D}.

Options

A.
trans-2-Methylcyclohexan-1-ol
B.
Cyclohexylmethanol
C.
1-Methylcyclohexan-1-ol
D.
Cycloheptanol

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Exception_Exposure

Learn to identify edge cases and boundary exceptions that JEE examiners hide in math problems.

Concepts Behind This Question

Hydroboration-Oxidation Logic|Steric Hindrance (B-Strain)

Why This Question Is Tricky

Common Mistakes

This problem tests the distinction between kinetic and thermodynamic control in hydroboration.

Students typically memorize the 'Textbook Rule' that hydroboration-oxidation yields the anti-Markovnikov alcohol (trans-2-methylcyclohexanol).

However, they often overlook the 'Hidden Variable' of thermal isomerization.

At elevated temperatures ( $160^\circ\text{C}$ ), organoboranes undergo reversible dehydroboration, allowing the boron atom to migrate to the least sterically hindered position to relieve B-strain.

The thermodynamic sink is the primary exocyclic carbon, leading to an unexpected regioselectivity that yields cyclohexylmethanol.

Quick Facts About This Question

Question Information

Subject	Chemistry
Chapter	Hydrocarbons - Class 11 Part 2
Concept	Hydroboration-Oxidation Logic
Difficulty	8
Cognitive Load	7
Target Solve Time	160 sec
Access	Free