See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Solution **Step 1: Identify product A (Grignard reaction)** Cyclohexanone reacts with $CH_3MgI$ followed by aqueous workup: $$\text{Cyclohexanone} + CH_3MgI \xrightarrow{H_2O} \text{A}$$ The Grignard reagent attacks the carbonyl carbon, forming a secondary alcohol with a methyl group attached to the ring: $$\text{A} = \text{1-methylcyclohexanol}$$ **Step 2: Identify product B (POCl₃ dehydration)** $POCl_3$ in pyridine at 0°C causes dehydration of the alcohol group in A, removing $H_2O$: $$\text{A} \xrightarrow{POCl_3, \text{pyridine}, 0°C} \text{B}$$ This converts the hydroxyl group ($-OH$) to a carbon-carbon double bond ($C=C$), forming an alkene with the methyl group still attached to the ring. **Step 3: Determine structure of B** The product is **1-methylcyclohexene**, with the methyl substituent and double bond on the same carbon: $$\text{B} = \text{methylcyclohexene with structure: six-membered ring with } C=CH_2 \text{ and } CH_3 \text{ groups}$$ **Why option (A) is correct:** Option (A) shows the correct structure with the methyl group ($CH_3$) and a double bond ($C=CH_2$) on the ring carbon. This matches the product formed by Grignard addition followed by dehydration, forming a substituted alkene.