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Question #44465

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The Question

A straight-chain alkene $\ce{A}$ ( $\ce{C8H16}$ ) undergoes syn-hydroxylation with cold, dilute alkaline $\ce{KMnO4}$ (Baeyer's reagent) to yield a single stereoisomer $\ce{B}$ which is a meso-diol. Let $x$ be the number of moles of $\ce{KMnO4}$ required to completely oxidize 1 mole of $\ce{A}$ to $\ce{B}$ under cold, dilute alkaline conditions. Let $y$ be the number of moles of $\ce{KMnO4}$ required to completely cleave 1 mole of $\ce{A}$ into carboxylic acids under hot, acidic conditions. Identify the correct values of $x$ and $y$ , and the IUPAC name of $\ce{A}$ .

Options

A.
$x = 2/3$ , $y = 8/5$ , (4Z)-oct-4-ene
B.
$x = 2/5$ , $y = 8/3$ , (4E)-oct-4-ene
C.
$x = 2/3$ , $y = 8/5$ , (4E)-oct-4-ene
D.
$x = 2/5$ , $y = 8/3$ , (4Z)-oct-4-ene

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Numerical_Precision

Improve calculation stamina and avoid rounding errors in high-stakes competitive examinations.

Concepts Behind This Question

Alkene Addition Regioselectivity|Equivalent Concept in Redox|KMnO4 Redox pH Dependency

Why This Question Is Tricky

Common Mistakes

The question tests the student's ability to integrate stereochemical regioselectivity (syn-addition yielding meso from cis) with rigorous redox stoichiometry.

A common trap is confusing the n-factors of $\ce{KMnO4}$ in different media (using 5 for alkaline or 3 for acidic) and failing to correctly calculate the n-factor of the organic substrate by tracking the oxidation state changes of the vinylic carbons during partial oxidation (diol) versus complete oxidative cleavage (carboxylic acid).

Quick Facts About This Question

Question Information

Subject	Chemistry
Chapter	Hydrocarbons - Class 11 Part 2
Concept	Alkene Addition Regioselectivity
Difficulty	8
Cognitive Load	7
Target Solve Time	160 sec
Access	Free