Tetrabutylammonium Peroxydisulfate in Organic Synthesis; IX: A Convenient Approach to the Synthesis of Fused Acetal Derivatives by Tetrabutylammonium Peroxydisulfate-Mediated Oxidative Cycloaddition of 1,3-Dicarbonyl Compounds to Cyclic Enol Ethers - Chen, Fen-Er; Fu, Han; Meng, Ge; Cheng, Yu; Hu, Ye-Li (Synthesis, 2000)