Tightly Convoluted Polymeric Phosphotungstate Catalyst:  An Oxidative Cyclization of Alkenols and Alkenoic Acids

A tightly convoluted polymeric phosphotungstate catalyst was prepared via ionic assembly of H<sub>3</sub>PW<sub>12</sub>O<sub>40</sub> and poly(alkylpyridinium). An oxidative cyclization of various alkenols and alkenoic acids was efficiently promoted by the polymeric catalyst in aq H<sub>2</sub>O<sub>2</sub> in the absence of organic solvents to afford the corresponding cyclic ethers and lactones in high yield. The catalyst was reused four times without loss of catalytic activity.