Identify the appropriate reagent to carry out the following transformation:

Step-by-step solution

The given transformation involves the conversion of a cyclic ketone (cyclopentanone) into a cyclic ester or lactone. This reaction is known as the Baeyer-Villiger oxidation, which inserts an oxygen atom adjacent to the carbonyl group. The Baeyer-Villiger oxidation is typically carried out using a peroxyacid (peracid) such as peroxybenzoic acid ( PhCO ₃ H ), meta-chloroperoxybenzoic acid (m-CPBA), or peracetic acid ( CH ₃ CO ₃ H ). Among the given options, PhCO ₃ H is a peroxyacid and is the appropriate reagent for