Question

Propose mechanisms for the epoxidation and ring-opening steps of the epoxidation and hydrolysis of shown above. Predict the product of the same reaction with.

Short answer

Answer

Step-by-step solution

Peroxyacid epoxidation

Peroxyacids can be used to convert alkenes to epoxides. The epoxides are known to open to a glycol if the reaction occur in an aqueous medium. For this reason, strong acids are avoided for the synthesis of epoxides.

Acid-catalyzed ring opening of epoxides

Epoxides react under both acidic and basic conditions. The products of the acid-catalyzed ring opening depend primarily on the solvent used.

Mechanisms 

In water as a solvent, the acid-catalyzed hydrolysis of epoxides forms glycols with anit-stereochemistry. The mechanism involves protonation of oxygen followed by attack by water. The back-side attack of water on the protonated epoxide results in anti-stereochemistry. Lastly, hydrolysis of epoxide occurs to give the glycol.