A chemistry student working in the laboratory failed to synthesize the diol using the reaction below. (i) Give the reason why this reaction fails. (ii) What are the modifications needed to synthesize the desired diol product?

• A. (i) The double bond interferes with the reaction of the Grignard reagent to the carbonyl group.(ii) Put an protecting group on the double bond first and then proceed with the reaction with the final step being the removal of the protecting group.
• B. (i) The alcohol group interferes with the reaction of the Grignard reagent to the carbonyl group.(ii) Put an protecting group on the OH group first and then proceed with the reaction with the final step being the removal of the protecting group.
• C. (i) The carbonyl interferes with the reaction of the Grignard reagent.(ii) Put an protecting group on the carbonyl group first and then proceed with the reaction with the final step being the removal of the protecting group.
• D. (i) The alcohol group would react to the carbonyl group.(ii) Put an protecting group on the double bond first and then proceed with the reaction with the final step being the removal of the protecting group.

Answer: (B)