Oxidation of cyclohexene with hot acidic ${\text{KMnO}}_4$ solution gives:

Hot acidic ${\text{KMnO}}_4$ is a vigorous oxidizing agent that causes oxidative cleavage of the double bond.In cyclohexene, the ring is broken at the double bond. Each $\text{CH}$ of the double bond is oxidized to a carboxylic acid group ($-\text{COOH}$).Structure: ${\text{HOOC(CH}}_2{\text{)}}_4\text{COOH}$. This is Adipic acid.