[4-Iodo-3-(isopropylcarbamoyl)phenoxy]acetic Acid as a Highly Reactive and Easily Separable Catalyst for the Oxidative Cleavage of Tetrahydrofuran-2-methanols to -Lactones

[4-Iodo-3-(isopropylcarbamoyl)phenoxy]acetic acid was developed as a highly reactive and easily separable catalyst for the oxidative cleavage of tetrahydrofuran-2-methanols to -lactones in the presence of Oxone((R)) (2KHSO(5)center dot KHSO4 center dot K2SO4) as the co-oxidant. The reactivity of this new catalyst was considerably greater than that of our previously reported catalyst, 2-iodo-N -isopropylbenzamide. The new catalyst and product were easily separated by only liquid-liquid separation without chromatography. In addition, using a mixture of nitromethane and N,N-dimethylformamide as the solvent and heating enabled a low catalyst loading, a short reaction time, and high product yield. Oxidative cleavage using the new catalyst can be used as a practical and efficient method for synthesizing gamma-lactones.