Let's break down the mechanism shown in the image, which is the **alkylation of the α-carbon** of a carbonyl compound. The specific reaction shown is an **enolate alkylation** using an alkyl halide (bromide). --- ## **Step-by-Step Mechanism** ### **1. Identify the Reactants** - **Cyclohexanone** (with an enolate already formed, as shown by the negative charge on the α-carbon and the oxygen anion) - **1-Bromopropene** (prop-1-enyl bromide) ### **2. The Enolate as a Nucleophile** The enolate ion (formed from cyclohexanone) is a strong nucleophile. - The **lone pair on the α-carbon** (the carbon with the negative charge) will attack the **electrophilic carbon** of the alkyl halide (the carbon attached to Br). ### **3. Alkyl Halide as Electrophile** - The **carbon attached to Br** in the alkyl halide is partially positive and susceptible to nucleophilic attack. ### **4. Curved Arrow Mechanism** **Draw the following curved arrows:** 1. **From the lone pair (negative charge) on the α-carbon** of the enolate **to the electrophilic carbon** of the alkyl halide (the carbon bonded to Br). 2. **From the C–Br bond to the Br atom**, indicating that the Br leaves as Br⁻ (bromide ion). This is an **SN2 reaction** at the alkyl halide. --- ## **Summary of Curved Arrows** 1. **Enolate α-carbon (nucleophile) attacks the alkyl halide carbon (electrophile).** 2. **Alkyl halide C–Br bond breaks, and Br leaves with a pair of electrons as Br⁻.** --- ## **Final Answer (Mechanism Explanation)** **Curved arrows to draw:** - From the lone pair (negative charge) on the α-carbon of the enolate to the terminal carbon of the alkyl bromide. - From the C–Br bond to the Br atom. **Result:** You get the alkylated product (with the new C–C bond at the α-position) and Br⁻ as the leaving group. --- ### **Visual Representation** ``` Step 1: O⁻ | / \ | | /-----\ + CH₂=CH-CH₂-Br | | Step 2 (Curved arrows): - Arrow from negative α-carbon to C of CH₂=CH-CH₂-Br - Arrow from C–Br bond to Br Step 3: O⁻ | / \ | | /-----\ | |----CH₂-CH=CH₂ (new bond) + Br⁻ ``` **That's the correct curved-arrow mechanism for this alkylation!**