University:
York University
Course:
CHEM 2021 | Introductory Organic Chemistry II
Academic year:

2023
Views:

479

Pages:

5
Author:

Niklas

**Baeyer-Villiger Oxidation** **Cyclic Ketones:** * Cyclic ketones react with mCPBA in DCM to form cyclic esters (lactones). * Cyclic ketones can also react with ammonia to form cyclic amides (lactams). **Acyclic Ketones:** * Acyclic ketones also undergo Baeyer-Villiger oxidation with mCPBA in DCM to form esters. * The migration of groups during this reaction follows a specific order: * H > 3° > Benzyl > Aryl > 2° > 1° > CH₃ **General Migration Rule:** * The group with the highest migratory aptitude migrates to the oxygen atom during the reaction. **Examples:** * Cyclopentanone reacts with mCPBA to form a cyclic ester (lactone). * Cyclohexanone reacts with ammonia to form a cyclic amide (lactam). * Phenyl methyl ketone reacts with mCPBA to form an ester where the phenyl group migrates. * tert-Butyl methyl ketone reacts with mCPBA to form an ester where the tert-butyl group migrates. **Note:** The migration order is a general guideline, and specific reaction conditions can influence the outcome. **Examples:** * **Aromatic Ketones:** * Phenyl methyl ketone reacts with mCPBA to form an ester where the phenyl group migrates. * **Cyclic Ketones:** * Cyclohexanone reacts with mCPBA to form a lactone. The migration of the hydrogen atom results in retention of configuration. **Mechanism (Migration):** [Image of a detailed mechanism showing the migration of a group during Baeyer-Villiger oxidation] The mechanism involves the following steps: 1. **Electrophilic Attack:** The peroxyacid (mCPBA) attacks the carbonyl carbon, forming a cyclic intermediate. 2. **Migration:** The group with higher migratory aptitude (usually a more substituted carbon) migrates to the oxygen atom, forming a new C-O bond. 3. **Rearrangement and Cleavage:** The intermediate rearranges to form a carbonyl oxide, which then cleaves to give the final ester product. The migration step is the key step in the Baeyer-Villiger oxidation, and the group with higher migratory aptitude will preferentially migrate.