Potential Degradation of 4‐Methyltetrahydropyran (4‐MeTHP) under Oxidation Conditions

Abstract

4‐Methyltetrahydropyran (4‐MeTHP) is a next‐generation recyclable ether solvent that can be applied to a wide variety of synthetic reaction methods. Previous studies indicated that 4‐MeTHP could degrade to some extent with certain oxidants, while the oxidation reactions themselves proceeded in good yields. Here we disclose the potential oxidative degradation pathways of 4‐MeTHP when exposed to selected organic‐based and metal‐based oxidants. Crude NMR analyses revealed that degradation of 4‐MeTHP was initiated by C2−H abstraction, giving rise to C2‐ or C4‐oxidized products or the C−C bond cleavage product depending on the oxidants used. This study therefore illustrates possible degradation products of 4‐MeTHP under oxidative conditions, which is particularly helpful in predicting and analyzing trace impurities when adopting 4‐MeTHP or other ethereal solvents in industrial processes.