Chapter 22, Problem 76PP

Interpretation Introduction

Interpretation:

Synthesis of cinnamaldehyde by using the suitable reagents should be identified.

Concept introduction:

Aldol condensation reaction is where the aldol addition product undergoes dehydration to give a conjugated enone.  In organic chemistry condensation reaction means loss of small molecules.  For aldol condensation reaction to take place the starting material should have two $\alpha$ hydrogens in the same carbon atom.  The driving force for aldol condensation reaction is the formation of conjugated system.  The steps involved in aldol condensation reaction are,

• Deprotonation of $\alpha$ carbon
• Attach of enolate ion with the aldehyde (nucleophilic attack)
• Protonation of the alkoxide ion to give aldol product
• Dehydration of the aldol addition product to form conjugated enone (aldol condensation product)

Please note that aldol condensation product is formed at higher temperature.

Note : Simple way to find the starting materials for aldol condensation product is to find the carbon-carbon double bond in the product. Break the bond and add oxygen to the $\beta$ position and two hydrogens to the $\alpha$ positions.