cinnamaldehyde

Cinnamaldehyde is an organic compound that provides the characteristic scent of cinnamon. Its chemical formula is C9H8O and its IUPAC name is (E)-3-phenylprop-2-enal. The molecule features a phenyl ring attached to a propenal chain with a conjugated C=C–C=O system, giving it both aromatic character and reactivity as an α,β-unsaturated aldehyde.

It is a major component of cinnamon bark essential oil, produced by Cinnamomum species such as Cinnamomum verum and Cinnamomum cassia. Commercially it can be extracted from cinnamon oil or prepared by chemical synthesis, for example by aldol condensation of benzaldehyde with acetaldehyde followed by dehydration, or by oxidation of cinnamyl alcohol.

Cinnamaldehyde exhibits typical properties of conjugated aldehydes: it is reactive in Michael-type additions and other reactions characteristic of aldehydes, and its conjugation with the aromatic ring influences its odor and stability. The compound can be sensitive to light and air, and may polymerize under certain conditions if not stabilized.

Uses for cinnamaldehyde are broad. It is widely employed as a flavoring agent in foods and beverages to impart a cinnamon flavor, and as a fragrance ingredient in perfumery and personal care products. It also serves as a starting material for the synthesis of various fragrances and pharmaceutical intermediates.

Safety considerations include irritation to the skin and eyes for some individuals, and it can act as a sensitizer. It is flammable and should be handled with appropriate precautions. In many jurisdictions it is permitted as a flavoring and fragrance ingredient within specified limits.