
Answer



🧪 Synthetic Scheme: Full Detailed Solution
Step 1: Enolate Formation (Deprotonation)
The α-hydrogen next to the ester group is acidic due to resonance stabilization of its conjugate base.
A strong base like NaOC₂H₅ abstracts the α-hydrogen, forming a carbanion intermediate.
Step 2: SN2 Reaction (First Alkylation)
The enolate ion attacks an alkyl halide (CH₃CH₂I) via the SN2 mechanism.
A C–C bond is formed at the α-position.
Mechanism: One-step backside attack with inversion of configuration (if applicable).
Step 3: Second Deprotonation and Alkylation
A second equivalent of NaOC₂H₅ removes another α-hydrogen.
The new carbanion then reacts with CH₂=CHCH₂Br (allyl bromide) via SN2.
Step 4: Hydrolysis and Decarboxylation
The diester undergoes hydrolysis using H₃O⁺ and heat, converting esters into carboxylic acids.
One of the β-keto acids then undergoes decarboxylation, releasing CO₂ and forming the final acid.
✅ Final Answer
Starting Material: 1
Reagents Used (in order):
i– NaOC₂H₅ (base for enolate formation)b– CH₃CH₂I (ethyl iodide)f– CH₂=CHCH₂Br (allyl bromide)j– H₃O⁺, heat (for hydrolysis and decarboxylation)
1ibfj
