(E)-2-Decenal is an α,β-unsaturated aldehyde naturally occurring in coriander, citrus peels, and certain meats. It imparts fatty, green, waxy, and soapy odor notes and is widely used as a flavor and fragrance ingredient. The compound features a trans-configured double bond between C2 and C3 adjacent to the aldehyde group, conferring reactivity typical of conjugated enals. It is approved for food use and contributes to the characteristic aroma profiles of various plant-derived foods. In chemical synthesis it serves as an intermediate for longer-chain compounds.