BAEYER-VILLIGER REARRANGEMENT.pptx

baeyer villiger rearrangment

1. BAEYER-VILLIGER REARRANGEMENT Presented by: M Abdullah Akmal Roll # : 908523 Rearrangement and Pericyclic Reactions

2. CONTENTS: History of Baeyer- Villiger Rearrangement Introduction of Baeyer- Villiger Rearrangement Example of Baeyer- Villiger Rearrangement Characteristics of Baeyer- Villiger Rearrangement Mechanism of Baeyer- Villiger Rearrangement Migratory Aptitude of Baeyer- Villiger Rearrangement Synthetic Applications of Baeyer- Villiger Rearrangement Reference

3. History of Baeyer- Villiger Rearrangement In 1899 A. Baeyer and V. Villiger described this reaction. Ketones could be transformed into esters peroxyacids. Cyclic ketones into lactones or hydroxy acids by peroxyacids .

4. Introduction of Baeyer-Villiger Rearrangement It is the rearrangement in which ketones are converted into esters and cyclic ketones into lactones, by which treatment with peracid.

5. Which Peracids are used in Baeyer-Villiger Rearrangement? Trifluoroperacetic acid Perbenzoic acid Peracetic acid Performic acid Monoperoxypthalic acid

6. Characteristics: Anionotropic rearrangement. Migration from Carbon to electron-deficient Oxygen. Electron donating group attached to migrating atom increase the rate of reaction. A buffer Solution Disodium phosphate must be added to prevent trans esterification. The activity of suitable oxidizing agents can be ranked in the following order: Trifluoro peroxyacetic acid > monopermaleic acid > monoperphthalic acid > 3,5-dinitroperbenzoic acid> p- nitroperbenzoic acid> meta chloroperoxybenzoic acid ( mCPBA )> performic acid > perbenzoic acid > peracetic acid > Hydrogen peroxide and finally tert-Butyl hydroperoxide.

7. Mechanism: Protonation of ketonic oxygen: The peroxide then undergoes loss of carboxylate anion and migration of a group from carbon to electron deficient oxygen to yield the protonated ester.

8. Mechanism:

9. Mechanism:

10. Example: A typical example of Baeyer-Villiger rearrangement is the reaction of acetophenone with perbenzoic acid at room temperature to produce phenylacetateA typical example of Baeyer-Villiger rearrangement is the reaction of acetophenone with perbenzoic acid at room temperature to produce phenylacetate.

11. Example: Another example is the reaction of alpha-diketones with peracid which gives anhydrides.

12. Migratory Aptitude: In an unsymmetrical ketone, that group migrates which is the better able to supply electrons. Amongst the alkyl group, the ease of migration is tertiary > secondary > primary > methyl.

13. Synthetic Applications: Baeyer-Villiger rearrangement has great synthetic utility as it permits the transformation of ketones into esters i.e. oxygen is inserted next to the carbonyl group. Synthesis of Lactones: Baeyer-Villiger rearrangement is a very useful method for the synthesis of cyclic ester called lactone.

14. Synthetic Applications: Synthesis of Anhydride: Only alpha-diketones react with peracid to produce anhydrides while all other diketones do not react with peracid. Synthesis of medicinal compounds: Baeyer-Villiger oxidation induced by fungus that produces Baeyer-Villiger monooxygenases, is used to transform the dehydroepiandrosterone ( androstenolone ) to an anticancer agent. This reaction was discovered in 2013 by Alina Swizdor .

15. Applications: Elucidation of structure: The ester obtained as a result of the rearrangement may be hydrolyzed to acid and alcohol from which the structure of the substrate can be determined. The reaction is not successful with aldehydes. Aliphatic aldehydes are oxidized to acids by the migration of the hydrogen. Aromatic Aldehydes have been converted to formats by the migration of the aryl group.

16. Recent research and trends: The Baeyer– Villiger oxidation of cyclic ketones using aqueous hydrogen peroxide as an oxidant over transition metal oxides yields the corresponding lactones. ➢ Silica-supported tricobalt tetra oxide catalysts have been employed for the Baeyer– Villiger oxidation of cyclohexanone under Mukaiyama conditions. ➢ Submicrometer -sized tin-containing MCM-41 particles with a size of several hundred nanometers were reported as selective catalysts for the Baeyer– Villiger oxidation of adamantanone with aqueous hydrogen peroxide. ➢ Chemoenzymatic Baeyer– Villiger oxidation of cyclic ketones catalyzed by Candida antarctica lipase B or Novozyme-435 suspended in an ionic liquid has been studied. ➢ Kinetic resolution of racemic 2-substituted cyclopentanones has been achieved via highly regio - and enantioselective Baeyer– Villiger oxidation.

17. Refrence : https://www.alfa.com/en/baeyer-villiger- oxidation/#:~:text=While%20exploring%20the%20ring%20cleavage,as%20t he%20Baeyer%2DVilliger%20oxidation . https://www.sigmaaldrich.com/PK/en/technical-documents/technical- article/chemistry-and-synthesis/organic-reaction-toolbox/ baeyer-villiger - oxidation-reaction . https://doi.org/10.1016/j.catcom.2014.04.017 https://doi.org/10.1007/s11144-014-0687-1 https://doi.org/10.1007/s40242-014-420 4-x https://doi.org/10.1039/c4nj01976h https://doi.org/10.1021/ol501737a Reactions, Rearrangement and Reagents by S N Sanyal Rearrangement and Pericyclic Reactions by Dr. Muhammad Shoaib