Hydrogen peroxide oxidation of polysubstituted pyrylium salts: Formation of enol esters and furans

Article abstract of DOI:10.1016/S0040-4020(01)92277-X

2,4,6-Trialkylsubstituted pyrylium salts 1 have been known to afford 2-acyl-3,5-dialkyl-furans 2 in moderate yields (30 - 45%). Oxidation of these salts in buffer solutions (pH = 3-4.5) increased the yields of acylfurans to 75%. In contrast, tetra- and pe