Every oxidation is accompanied by a reduction. Identify the species that is reduced in the Swern oxidation in Assessment 13.48.

Verified step by step guidance

1. Understand the Swern oxidation: It is a chemical reaction used to convert primary and secondary alcohols to aldehydes and ketones, respectively, using dimethyl sulfoxide (DMSO) and oxalyl chloride (COCl₂) in the presence of a base like triethylamine.
2. Identify the role of DMSO: In the Swern oxidation, DMSO acts as the oxidizing agent. It is converted to a sulfonium ion intermediate during the reaction.
3. Recognize the reduction process: During the Swern oxidation, DMSO is reduced to dimethyl sulfide (DMS), which is the species that is reduced in this reaction.
4. Consider the overall reaction: The alcohol is oxidized to an aldehyde or ketone, while DMSO is reduced to DMS. This demonstrates the principle that every oxidation is accompanied by a reduction.
5. Review the mechanism: The mechanism involves the formation of an activated DMSO complex, which facilitates the transfer of oxygen from DMSO to the alcohol, resulting in the reduction of DMSO to DMS.

Key Concepts

Swern Oxidation

Swern oxidation is a chemical reaction used to convert primary and secondary alcohols into aldehydes and ketones, respectively. It involves the use of dimethyl sulfoxide (DMSO) activated by oxalyl chloride, followed by the addition of a base like triethylamine. Understanding the reagents and the mechanism is crucial for identifying the species involved in the oxidation and reduction processes.

Oxidation-Reduction (Redox) Reactions

Redox reactions involve the transfer of electrons between two species, where one species is oxidized (loses electrons) and the other is reduced (gains electrons). In the context of Swern oxidation, identifying the species that undergoes reduction is essential, as it complements the oxidation of the alcohol substrate. Recognizing electron transfer and changes in oxidation states is key to understanding these reactions.

Role of Dimethyl Sulfoxide (DMSO)

In Swern oxidation, DMSO acts as the oxidizing agent, facilitating the conversion of alcohols to carbonyl compounds. During the reaction, DMSO is reduced to dimethyl sulfide, which is the species that gains electrons. Understanding the transformation of DMSO and its role in the mechanism helps in identifying the reduced species in the reaction.