A reaction for converting ketones to lactones, called the Baeyer-Villiger reaction, is used in the manufacture of plastics and pharmaceuticals. 3-Chloroperbenzoic acid is shock-sensitive, however, and prone to explode. Also, 3 -chlorobenzoic acid is a waste product. An alternative process being developed uses hydrogen peroxide and a catalyst consisting of tin deposited within a solid support. The catalyst is readily recovered from the reaction mixture. (a) What would you expect to be the other product of oxidation of the ketone to lactone by hydrogen peroxide? (b) What principles of green chemistry are addressed by use of the proposed process?

The Baeyer-Villiger reaction is an organic reaction that involves the conversion of ketones into esters or lactones by the addition of a peracid. In this case, hydrogen peroxide (H2O2) is used as the peracid.

During the Baeyer-Villiger reaction, a ketone is oxidized to a lactone, while the peracid (hydrogen peroxide) will be reduced to another product. To identify the other product, we need to consider the reduction of hydrogen peroxide. The reduction of hydrogen peroxide can be represented by the following half-reaction: H2O2 + 2 H^+ + 2e^- -> 2 H2O In this reaction, hydrogen peroxide is reduced by receiving 2 electrons and 2 protons, transforming into water (H2O) as the other product of the oxidation of the ketone to lactone.

Green chemistry aims to design products and processes that minimize the use and generation of hazardous substances. The proposed process involving hydrogen peroxide and a tin catalyst addresses several principles of green chemistry: 1. Use of safer reactants: Hydrogen peroxide is a less hazardous alternative to 3-chloroperbenzoic acid, which is shock-sensitive and prone to explode. 2. Waste prevention: The proposed process avoids the formation of 3-chlorobenzoic acid as a waste product, which could have environmental and disposal issues. 3. Catalytic processes: The use of a tin catalyst deposited within a solid support can help reduce the amount of reactants needed, making the process more efficient and generating less waste. The catalyst can be easily separated from the reaction mixture and reused, contributing to waste reduction. 4. Renewable feedstocks: Hydrogen peroxide is a simple and readily available chemical that can be produced from environmental sources like water and oxygen, making it more sustainable than other peracids. In conclusion, the other product of oxidation of the ketone to lactone by hydrogen peroxide is water (H2O), and the proposed process addresses several principles of green chemistry such as the use of safer reactants, waste prevention, catalytic processes, and renewable feedstocks.