19.8 Baeyer Villiger Oxidation | Organic Chemistry

Chad's Prep
6 Apr 202106:17
EducationalLearning
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TLDRThe video script discusses the Baeyer-Villiger oxidation, a chemical reaction that converts ketones to esters and aldehydes to carboxylic acids using a peroxy acid. The most famous peroxy acid mentioned is meta-chloro-benzoic acid (MCPBA). The reaction mechanism involves a nucleophilic attack by the peroxy acid on the ketone, leading to the formation of an intermediate. A proton transfer reaction follows, resulting in the insertion of oxygen on the more substituted side of the alpha carbon. The process concludes with a rearrangement that forms a new bond between the carbon and oxygen, expanding a five-membered ring to a six-membered ring with an ester or a carboxylic acid as the byproduct. The video emphasizes the stability of the reaction, noting that the oxygen insertion occurs on the more substituted side due to partial positive charge buildup, akin to the stability of a more substituted carbocation. The lesson is part of an organic chemistry series released weekly and is available on the instructor's channel.

Takeaways
  • πŸ§ͺ The Baeyer-Villiger oxidation is a chemical reaction that converts ketones into esters and aldehydes into carboxylic acids using a peroxy acid.
  • πŸ” The reaction mechanism involves a nucleophilic attack by the peroxy acid, leading to the formation of an intermediate and subsequent rearrangement.
  • β­• The oxygen from the peroxy acid inserts into the molecule on the side of the more substituted alpha-carbon adjacent to the carbonyl group.
  • πŸ”„ For cyclic ketones, the reaction results in an expansion of the ring, while for open-chain ketones, it forms an open-chain ester.
  • πŸ“š The most famous peroxy acid used in this reaction is meta-chloroperoxybenzoic acid (mCPBA), which is also used for converting alkenes into epoxides.
  • ⏩ The reaction proceeds through an intramolecular proton transfer, leading to the formation of a new bond between the carbon and the oxygen.
  • 🚫 There is no actual carbocation intermediate formed during the reaction, but there is a buildup of partial positive charge on the carbon during the transition state.
  • πŸ”¬ The partial positive charge is more stable on a more substituted carbon, which is why the oxygen inserts on the more substituted side.
  • πŸ“ˆ The product formed depends on the initial substrate; cyclic ketones yield cyclic esters, while open-chain ketones yield open-chain esters.
  • ⏫ In the case of aldehydes, the reaction always substitutes on the hydrogen side, resulting in the formation of a carboxylic acid.
  • πŸ“š For aldehydes, other methods such as using chromic acid can also be used to convert them into carboxylic acids, although the Baeyer-Villiger oxidation is a specific method for this transformation.
Q & A
  • What is the main topic of this lesson?

    -The main topic of this lesson is the Baeyer-Villiger oxidation, which involves converting a ketone to an ester or an aldehyde to a carboxylic acid using a peroxy acid.

  • What is a peroxy acid and how does it relate to the Baeyer-Villiger oxidation?

    -A peroxy acid is a compound that resembles a carboxylic acid but has an extra oxygen atom. It is used in the Baeyer-Villiger oxidation to insert an oxygen atom into the molecule, converting ketones to esters and aldehydes to carboxylic acids.

  • Which side of the ketone does the oxygen insert into during the Baeyer-Villiger oxidation?

    -The oxygen inserts into the side of the ketone that has the more substituted alpha-carbon (the carbon adjacent to the carbonyl group).

  • What happens when an aldehyde undergoes Baeyer-Villiger oxidation?

    -When an aldehyde undergoes Baeyer-Villiger oxidation, a carboxylic acid is formed, as the oxygen inserts next to the hydrogen on the less substituted side of the carbonyl group.

  • What is the most famous peroxy acid mentioned in the script?

    -The most famous peroxy acid mentioned is meta-chloro-peri-benzoic acid (MCPBA).

  • How does the mechanism of Baeyer-Villiger oxidation begin?

    -The mechanism begins with a nucleophilic attack by the oxygen atom farthest from the carbonyl group, pushing electrons up to the oxygen atom, leading to the formation of an intermediate.

  • What type of rearrangement occurs during the Baeyer-Villiger oxidation mechanism?

    -A funky rearrangement occurs where a bond forms between the carbon and the oxygen, leading to the insertion of oxygen into the molecule and the formation of a new ester or carboxylic acid.

  • Why does the oxygen insert on the more substituted side of the ketone?

    -The oxygen inserts on the more substituted side because there is a buildup of partial positive charge on the carbon during the transition state, which is more stable on a more substituted carbon.

  • What is the byproduct formed when the Baeyer-Villiger oxidation is complete?

    -The byproduct formed is a carboxylic acid.

  • How often are the organic chemistry lessons released by the speaker?

    -The organic chemistry lessons are released weekly throughout the school year.

  • What does the speaker suggest to ensure other students can see the lesson?

    -The speaker suggests liking and sharing the lesson to help other students discover it.

  • Where can one find a study guide and practice problems on ketones and aldehydes?

    -One can find a study guide and practice problems on ketones and aldehydes in the speaker's premium course on Chatsprep.com.

Outlines
00:00
πŸ§ͺ Introduction to Baeyer-Villiger Oxidation

This paragraph introduces the Baeyer-Villiger oxidation, a chemical reaction that converts ketones into esters and aldehydes into carboxylic acids using a peroxy acid. The focus is on predicting the products and understanding the reaction mechanism. The presenter also mentions the use of a well-known peroxy acid, meta-chloroperoxybenzoic acid (MCPBA), and compares the process to the conversion of alkenes into epoxides. The insertion of oxygen on the more substituted alpha-carbon adjacent to the carbonyl group is emphasized, and the formation of either a cyclic or open chain ester is discussed.

05:04
πŸ” Mechanism of Baeyer-Villiger Oxidation

The second paragraph delves into the mechanism of the Baeyer-Villiger oxidation. It begins with a nucleophilic attack by the oxygen atom of the peroxy acid on the ketone, leading to an intermediate. A proton transfer reaction follows, which is an intramolecular process that results in the deprotonation of one oxygen and protonation of another. The mechanism then involves a rearrangement where a bond forms between the carbon and oxygen, leading to the opening of the original ring and the formation of a new ester. The byproduct of this reaction is a carboxylic acid. The paragraph also discusses the partial positive charge buildup on the carbon during the reaction, explaining why the oxygen inserts on the more substituted side, drawing parallels to the stability of more substituted carbocations.

Mindmap
Keywords
πŸ’‘Baeyer-Villiger Oxidation
The Baeyer-Villiger Oxidation is a chemical reaction that converts ketones into esters or aldehydes into carboxylic acids using a peroxy acid. It is a key topic in the video, illustrating the transformation of organic compounds through the insertion of an oxygen atom. The reaction is significant in organic chemistry for its synthetic utility and is exemplified in the script with both cyclic and open-chain ketones.
πŸ’‘Peroxy Acid
A peroxy acid, such as meta-chloro-peroxy-benzoic acid (mCPBA), is a key reagent in the Baeyer-Villiger Oxidation. It is structurally similar to a carboxylic acid but contains an additional oxygen atom. In the video, peroxy acids are shown to facilitate the insertion of oxygen into the substrate, leading to the formation of esters or carboxylic acids, depending on the starting material.
πŸ’‘Ketones
Ketones are organic compounds with a carbonyl group (C=O) where the carbon atom is bonded to two other carbon atoms. In the context of the video, ketones are transformed into esters through the Baeyer-Villiger Oxidation. The reaction is illustrated with a cyclic ketone, but the script clarifies that the process is applicable to both cyclic and open-chain ketones.
πŸ’‘Esters
Esters are organic compounds derived from an acid (or in this case, a ketone) where the hydroxyl group of the acid is replaced by an alkoxy group. In the video, the Baeyer-Villiger Oxidation is shown to produce esters from ketones, with the oxygen insertion occurring on the more substituted alpha-carbon adjacent to the carbonyl group.
πŸ’‘Aldehydes
Aldehydes are a class of organic compounds containing a terminal carbonyl group bonded to a hydrogen atom. The video discusses the conversion of aldehydes to carboxylic acids through the Baeyer-Villiger Oxidation, emphasizing that the oxygen always inserts on the hydrogen side of the carbonyl group.
πŸ’‘Carboxylic Acids
Carboxylic acids are organic compounds with a carboxyl group (-COOH). In the script, it is mentioned that aldehydes can be converted into carboxylic acids using the Baeyer-Villiger Oxidation, although other methods like chromic acid are also known for this transformation.
πŸ’‘Alpha-Carbon
The alpha-carbon refers to the carbon atom adjacent to the carbonyl group in a carbonyl compound. In the context of the video, the oxygen from the peroxy acid inserts into the position of the more substituted alpha-carbon, which is crucial for determining the product of the Baeyer-Villiger Oxidation.
πŸ’‘Mechanism
The term 'mechanism' in the video refers to the step-by-step process by which the Baeyer-Villiger Oxidation occurs. The script outlines a nucleophilic attack, followed by a proton transfer and rearrangement, leading to the formation of an ester or carboxylic acid. Understanding the mechanism is essential for grasping how the reaction proceeds and why certain products are formed.
πŸ’‘Nucleophilic Attack
A nucleophilic attack is a fundamental concept in organic chemistry where a nucleophile (an electron-rich species) donates a pair of electrons to an electrophile (an electron-deficient species). In the video, the nucleophilic attack by the oxygen of the peroxy acid on the ketone sets the stage for the Baeyer-Villiger Oxidation.
πŸ’‘Proton Transfer
A proton transfer is a type of reaction where a hydrogen ion (proton) is moved from one molecule to another. In the video, an intramolecular proton transfer occurs, which is a crucial step in the rearrangement leading to the formation of the ester in the Baeyer-Villiger Oxidation.
πŸ’‘Partial Positive Charge
The concept of a partial positive charge refers to an uneven distribution of electrons within a molecule, resulting in a localized positive charge. The video explains that the partial positive charge buildup on the alpha-carbon influences the side of oxygen insertion during the Baeyer-Villiger Oxidation, favoring the more substituted carbon for greater stability.
Highlights

The lesson focuses on the Baeyer-Villiger oxidation, a chemical reaction that converts ketones to esters and aldehydes to carboxylic acids using a peroxy acid.

Peroxy acids, like meta-chloroperoxybenzoic acid (MCPBA), are similar to carboxylic acids but with an extra oxygen atom.

The reaction mechanism involves a nucleophilic attack by the oxygen furthest from the carbonyl group, leading to an intermediate formation.

A proton transfer reaction occurs within the molecule, deprotonating one oxygen and protonating another.

The oxygen inserts itself into the more substituted side of the alpha carbon adjacent to the carbonyl group.

For cyclic ketones, the reaction results in an increase in the ring size, while for open chain ketones, it forms an open chain ester.

In the case of aldehydes, the oxygen always inserts on the hydrogen side, leading to the formation of a carboxylic acid.

The mechanism involves a rearrangement where a bond forms between the carbon and oxygen, resulting in the expansion of the ring size.

The byproduct of the reaction is a carboxylic acid, indicating the transfer of an oxygen atom from the peroxy acid to the substrate.

The partial positive charge buildup on the carbon during the transition state is a key factor in determining where the oxygen inserts.

The insertion occurs on the more substituted side, which is more stable due to the higher substrate carbon.

The lesson provides a detailed explanation of the Baeyer-Villiger oxidation mechanism, which is crucial for understanding organic chemistry.

The video is part of a weekly organic chemistry playlist released throughout the school year.

Viewers are encouraged to subscribe to the channel and click the bell notification to be updated on new lesson releases.

The lesson includes a discussion on how to predict the products of the Baeyer-Villiger oxidation.

The importance of understanding the stability of carbocations in relation to the reaction mechanism is emphasized.

The lesson is designed to help students grasp the theoretical and practical aspects of the Baeyer-Villiger oxidation.

Additional resources, such as a study guide and practice problems, are available on chatsprep.com for those seeking further assistance.

Transcripts
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