Pyrylium salt
（重定向自Flavylium）
The pyrylium cation is a six-membered, unsaturated, mono-cyclic compound. Consisting of five carbon atoms and one positively charged oxygen atom, it is a heterocyclic compound, resembling benzene with one substitution in the ring. Like benzene, it is aromatic, and a conjugated system. Having three bonds on its positively charged oxygen atom, pyrylium is an oxonium ion.