Let's break down the retrosynthesis and then write the **forward sequence** with step-by-step explanations. --- ## **Retrosynthesis Analysis** Given target molecule: Aldehyde + ketone with a dimethylamino group on the side chain. Retrosynthetic steps (from right to left): 1. **First Step (Rightmost Arrow):** The target molecule can be formed by **Michael addition** of dimethylamine to the α,β-unsaturated ketone. 2. **Second Step (Middle Arrow):** The α,β-unsaturated ketone can be formed from an **aldol condensation** between a benzaldehyde and an acetophenone derivative. 3. **Third Step (Leftmost Arrow):** The benzaldehyde and acetophenone can be connected via **aldol reaction**. --- ## **Forward Sequence (Step-by-Step)** ### **Step 1: Aldol Condensation** - **Reactants:** 4-dimethylaminobenzaldehyde + 4'-acetylacetophenone (or a similar acetophenone derivative) - **Reagents/Conditions:** Base (e.g., NaOH, EtOH, H₂O), heat - **Transformation:** The aldehyde (more reactive than ketone) undergoes an aldol condensation with the ketone to form the α,β-unsaturated ketone. - **Product:** α,β-unsaturated ketone (enone) ### **Step 2: Michael Addition** - **Reactants:** α,β-unsaturated ketone (from Step 1) Dimethylamine (Me₂NH) - **Reagents/Conditions:** Me₂NH, solvent (e.g., ethanol), mild base (optional) - **Transformation:** Michael addition of dimethylamine to the β-carbon of the enone. - **Product:** The final product, where the dimethylamino group is attached at the β-position relative to the original ketone. --- ## **Summary Table** | Step | Reaction Type | Reagents/Conditions | Transformation | Product | |------|----------------------|----------------------------|----------------------------------|----------------------------------| | 1 | Aldol Condensation | NaOH, EtOH, H₂O, heat | Benzaldehyde + Acetophenone → α,β-unsaturated ketone | Enone (α,β-unsaturated ketone) | | 2 | Michael Addition | Me₂NH, EtOH | Enone + Me₂NH → β-amino ketone | Target molecule | --- ## **Final Forward Sequence** 1. **Aldol Condensation:**  *4-dimethylaminobenzaldehyde + 4'-acetylacetophenone, NaOH, EtOH, heat* → α,β-unsaturated ketone 2. **Michael Addition:**  *α,β-unsaturated ketone + Me₂NH, EtOH* → Final product --- ### **Final Answer** **Forward sequence:** 1. **Aldol condensation** between 4-dimethylaminobenzaldehyde and 4'-acetylacetophenone with base (NaOH, EtOH). 2. **Michael addition** of dimethylamine (Me₂NH) to the α,β-unsaturated ketone product. This sequence exploits the higher reactivity of the aldehyde to selectively form the aldol product before the Michael addition.