Step 1: Understanding the Question:
The question asks for the product of the reaction between an alkene and Baeyer's reagent (cold, dilute, alkaline \( \text{KMnO}_4 \)).
Step 3: Detailed Explanation:
Cold, dilute, alkaline potassium permanganate solution is known as Baeyer's reagent.
When an alkene reacts with this reagent, it undergoes syn-hydroxylation.
The purple color of \( \text{KMnO}_4 \) disappears, and a brown precipitate of \( \text{MnO}_2 \) is formed.
Two hydroxyl (\( \text{-OH} \)) groups are added across the double bond of the alkene to form a vicinal diol, which is commonly known as a Glycol.
For example: \( \text{CH}_2\text{=CH}_2 + \text{H}_2\text{O} + [\text{O}] \xrightarrow{\text{alkaline KMnO}_4} \text{CH}_2(\text{OH})-\text{CH}_2(\text{OH}) \) (Ethylene glycol).
Step 4: Final Answer:
The product obtained is Glycol.