Oxidative cleavage of alkenes by hot KMnO4

Steps:

• Hot, concentrated acidified manganate(VII) cleaves C=C bonds in alkenes oxidatively.
• =CH2 group becomes CO2; =CHR becomes RCOOH; =CR1R2 becomes R1COR2.
• Identify alkene substitution: one side needs =CHR for carboxylic acid, other =CR1R2 for ketone.
• Match options to substitution pattern yielding one acid and one ketone.

Why D is correct:

• D is an unsymmetrical alkene with =CH-R and =C(CH3)2, cleaving to RCOOH and (CH3)2C=O per oxidative rules.

Why the others are wrong:

• A: Symmetrical internal alkene (=CR2 both sides) yields two ketones.
• B: Terminal alkene (=CH2 and =CHR) yields CO2 and carboxylic acid, no ketone.
• C: 1,2-disubstituted alkene (=CHR both sides) yields two carboxylic acids.

Final answer: D