Let's solve each question step-by-step and provide explanations: --- ## 1. Imine Formation with a Secondary Amine ### Step 1: Identify Reactants and Reaction Type - Starting material: Ketone (2-pentanone) - Reagent: Methylamine (CH₃NH₂), trace acid - Reaction: Ketone + secondary amine → **enamine** (since secondary amines form enamines, not imines). **Explanation:** Secondary amines react with ketones to form enamines via nucleophilic addition-elimination. --- ### Step 2: Draw the Product Structure - The enamine forms at the α-carbon (adjacent to the carbonyl). - The product: The double bond forms between the α-carbon and the β-carbon; the methylamino group is attached to the nitrogen. **Explanation:** Proton removal from the α-carbon leads to enamine formation. **Final Answer:** The product is: ``` CH3 | CH3—C=CH—N—CH3 | CH2CH3 ``` or, in line structure: ``` CH3 | /-----N—CH3 | | | CH2CH3 | CH3 ``` --- ## 2. Enamine Formation (Reverse Reaction) ### Step 1: Identify the Enamine Structure - Target: Cyclohexanone enamine (five-membered ring with N attached to cyclopentyl group). **Explanation:** Enamines are made by reacting a ketone/aldehyde with a secondary amine. --- ### Step 2: Identify the Reactants - The enamine is formed from **cyclohexanone** and **pyrrolidine** (a five-membered secondary amine). **Explanation:** The carbonyl of cyclohexanone reacts with the nitrogen of pyrrolidine. **Final Answer:** Reactants are: - Cyclohexanone - Pyrrolidine ``` O N / \ + /-----\ | | | | \ / \-----/ ``` --- ## 3. Wittig Reaction ### Step 1: Identify the Product Structure - Target: An alkene where phenyl (benzyl) group is attached to the double bond (styrene derivative). **Explanation:** Wittig reaction forms alkenes from aldehydes/ketones and phosphonium ylides. --- ### Step 2: Identify the Reactants - Reactants: - The corresponding aldehyde (butanal) - The ylide (Ph₃P=CHPh, triphenylphosphonium benzylide) **Explanation:** The ylide reacts with the carbonyl carbon to form the desired alkene. **Final Answer:** Reactants are: - Butanal (CH₃CH₂CH₂CHO) - Benzyl triphenylphosphonium ylide (Ph₃P=CHPh) --- ## 4. Baeyer–Villiger Oxidation ### Step 1: Recognize the Reaction - Starting material: Ketone (2,2-dimethyl-3-pentanone) - Reagent: Peracid (CH₃CO₃H, peracetic acid) - Reaction: Baeyer–Villiger oxidation (inserts an oxygen next to the carbonyl, converting ketone to ester). **Explanation:** The more substituted alkyl migrates to the oxygen. --- ### Step 2: Predict the Product Structure - Oxygen is inserted between the carbonyl and the more substituted (tert-butyl) group. **Explanation:** The tert-butyl group migrates, forming tert-butyl acetate. **Final Answer:** Product is: - tert-butyl acetate ``` O || CH3-C-O-C(CH3)3 ``` --- ### **Summary Table** | # | Step 1 | Step 2 | Final Answer | |---|--------|--------|--------------| | 1 | Ketone + MeNH₂ | Enamine | Enamine structure | | 2 | Target enamine | Ketone + 2° amine | Cyclohexanone + pyrrolidine | | 3 | Alkene (styrene) | Aldehyde + ylide | Butanal + Ph₃P=CHPh | | 4 | Ketone + peracid | Ester | tert-butyl acetate | Let me know if you want structures in a different style or more detailed mechanisms!