Question

Compound A (C₆H₁₂; reacts with 1 molar equivalent of H₂ over a Pd catalyst) gives the product(s) below on oxidative cleavage with KMnO₄ in acidic solution.

Propose a structure for A.

Compound A ➝ CH₃CH₂CO₂H + a ketone

Answer 1

Compound A is likely 3-hexene (CH3CH2CH=CHCH2CH3), as its oxidative cleavage with KMnO₄ would account for the formation of acetic acid and a three-carbon ketone, matching the description of the products given by the student.

Step-by-step explanation:

The student's question involves identifying the structure of a hydrocarbon (Compound A) that reacts with hydrogen over a Palladium (Pd) catalyst and undergoes oxidative cleavage with potassium permanganate (KMnO₄) to give acetic acid (CH3CH2CO2H) and a ketone as products.

Since the chemical formula for Compound A is C₆H₁₂ and it reacts with one molar equivalent of H₂, this indicates that Compound A is an alkene. Moreover, oxidative cleavage by KMnO₄ resulting in acetic acid and a ketone suggests it is a di-substituted alkene, with one part becoming acetic acid and the other a ketone upon cleavage.

By analyzing the products, we determine that the alkene has an ethyl group on one end (forming acetic acid upon oxidation) and a carbon chain that would form a ketone upon cleavage.

This suggests that Compound A could be 3-hexene, as the cleavage of this alkene would lead to the formation of acetic acid and a three-carbon ketone (propanone). Therefore, the proposed structure for Compound A is CH3CH2CH=CHCH2CH3, which upon hydrogenation becomes hexane and under KMnO₄ oxidative cleavage yields CH3CH2CO2H and a ketone.