Thiophene is a five-membered heterocyclic compound containing a sulfur heteroatom with the molecular formula C4H4S. Thiophene is aromatic and is very similar to benzene; electrophilic substitution reaction is easier than benzene, and it is mainly substituted at the 2-position. Thiophene ring system has certain stability to oxidant.
Pyrones or pyranones are a class of heterocyclic chemical compounds. They contain an unsaturated six-membered ring containing one oxygen atom and a ketone functional group. There are two isomers denoted as 2-pyrone and 4-pyrone. 2-Pyrone is used in organic synthesis as a building block for more complex chemical structures because it may participate in a variety of cycloaddition reactions to form bicyclic lactones. Pyrone derivatives are extremely prevalent structural motif in diverse naturally and synthetically occurring bioactive molecules having a broad array of chemotherapeutic potentials.