Aromatic compounds are a class of organic compounds that contain one or more benzene rings. Esters (6 letters) are a type of aromatic compound that are formed when an acid reacts with an alcohol, and they have a distinct sweet smell. ESTER (5 letters) is the general name for any compound formed from an acid and an alcohol. Oxides (6 letters) are also a type of aromatic compound, and they are formed when oxygen combines with another element.