Answer
Detailed Mechanism of a Multi-Step Organic Reaction
Step 1: Ozonolysis of Cyclohexene
The reaction begins with cyclohexene undergoing ozonolysis using O3 followed by Me2S. This cleaves the double bond to form two molecules of adipaldehyde (OHC-(CH2)4-CHO).
Step 2: Reaction with Grignard Reagent (CH3MgBr)
Each aldehyde group reacts with one equivalent of the Grignard reagent CH3MgBr. This adds a methyl group and converts each aldehyde into a secondary alcohol, resulting in:
HO-CH(CH3)-(CH2)4-CH(CH3)-OH
Step 3: Oxidation using Na2Cr2O7/H2SO4
The diol formed is then oxidized using a strong oxidizing agent, Na2Cr2O7 in H2SO4. This oxidizes the two secondary alcohols to ketones, giving the final product:
CH3-CO-(CH2)4-CO-CH3
Final Answer and Identification
Comparing this structure with the options, the correct product matches Option B: a six-carbon chain with two terminal methyl ketones.