Glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) form. The naturally occurring form of glucose is d-glucose, while its stereoisomer l-glucose is produced synthetically in comparatively small amounts and is less biologically active.
Benzene is an important organic compound with the chemical formula C6H6, and its molecule consists of a ring of 6 carbon atoms, each with 1 hydrogen atom. Benzene is a sweet, flammable, colorless and transparent liquid with carcinogenic toxicity at room temperature, and has a strong aromatic odor. It is insoluble in water, easily soluble in organic solvents, and can also be used as an organic solvent itself. The ring system of benzene is called benzene ring, and the structure after removing one hydrogen atom from the benzene ring is called phenyl. Benzene is one of the most important basic organic chemical raw materials. Many important chemical intermediates can be derived from benzene through substitution reaction, addition reaction and benzene ring cleavage reaction.