Reaction Sequence Analysis

The given reaction sequence involves a cyclic ketone undergoing a series of transformations. Let's analyze it step by step:

Step 1: Identify the Starting Compound

The starting compound is a 6-membered cyclic ketone (cyclohexanone derivative). The reaction with CH₃MgBr (Grignard reagent) followed by H₃O⁺ is a nucleophilic addition reaction. The Grignard reagent adds to the carbonyl carbon, converting the ketone to a tertiary alcohol.

Reaction: $Ketone + CH 3 MgBr \to Tertiary alcohol$

Step 2: Dehydration with Conc. H₂SO₄

The tertiary alcohol undergoes dehydration (elimination of water) when treated with concentrated H₂SO₄. This results in the formation of an alkene. Since the alcohol is tertiary, the elimination follows Zaitsev's rule, giving the more substituted alkene.

Reaction: $Tertiary alcohol \overset{Conc. H 2 SO 4}{\to} Alkene + H 2 O$

Step 3: Ozonolysis

The alkene from step 2 is subjected to ozonolysis (O₃ followed by Zn/H₂O). Ozonolysis cleaves the double bond, converting each carbon of the double bond into a carbonyl group. For a cyclic alkene, this ring-opening occurs.

Reaction: $Alkene \overset{1. O 3, 2. Zn/H 2 O}{\to} Carbonyl compounds$

Step 4: Predict the Product (X)

The starting cyclic ketone is symmetric (cyclohexanone). After Grignard addition and dehydration, the alkene formed is 1-methylcyclohexene. Ozonolysis of 1-methylcyclohexene cleaves the double bond, giving a dialdehyde. Specifically, it produces OHC-(CH₂)₄-CHO (hexanedial).

Final product (X) is: $OHC - (CH 2) 4 - CHO$

Comparing with the options, the correct structure is the one with two aldehyde groups at the ends of a 6-carbon chain.

Final Answer

The compound (X) is: Hexanedial structure

Related Topics

Grignard Reaction
Dehydration of Alcohols
Ozonolysis of Alkenes
Carbonyl Chemistry

Important Formulae and Theory

Grignard Addition: R-MgBr + carbonyl compound → alcohol after hydrolysis.

Dehydration: Alcohol $\overset{acid}{\to} alkene + H 2 O$

Ozonolysis: Alkene + O₃ → ozonide $\overset{Zn/H 2 O}{\to} carbonyl compounds$

Zaitsev's Rule: In elimination, the more substituted alkene is favored.