ChemInform Abstract: Chemistry of Enol Ethers. Part 73. Synthesis of Pyrylium Salts from the Monoacetals of 1,5‐Dicarbonyl Compounds.

Abstract The reaction of the unsubstituted or the methylsubstituted 5,5‐diethoxy‐pentenals (II) and the 4,6,6‐triethoxy‐hexanones (V) with HClO4 or H2[SnC16] yields the pyrylium salts (III) or (VI), which are difficult to prepare by previous methods.