Alternative method to Baeyer–Villiger oxidation of cyclobutenones using I2/DMSO catalytic systems†

The Baeyer–Villiger oxidation represents a valuable reaction that enables the conversion of ketones into esters or lactones. Here, we present a novel and efficient approach utilizing I₂ as a catalyst for the oxidative rearrangement of cyclobutenones, resulting in the synthesis of furan-2(5H)-one. Notably, this method employs dimethyl sulfoxide (DMSO) as a greener oxidant and source of oxygen. The reaction proceeds smoothly with catalytic amounts of iodine, yielding lactones in good yields. Compared to conventional Baeyer–Villiger oxidation reactions that rely on peroxyl acids or hydrogen peroxide, the use of DMSO offers a safer and more versatile alternative.