geranial

Geranial, also called (2E)-3,7-dimethyl-2,6-octadienal, is an unsaturated aliphatic aldehyde and one of the two geometric isomers that make up citral. It is also known as trans-citral or alpha-citral, with its isomer neral (the Z isomer, or cis-citral) forming the other component.

Geranial is a ten-carbon monoterpene aldehyde with a conjugated diene system adjacent to the aldehyde group, and the 2-alkene exists in the E configuration. It occurs naturally in the essential oils of various plants, most notably lemongrass (Cymbopogon citratus), where it often dominates along with neral. In essential oils it is typically present as part of the citral mixture and can be isolated by distillation and purification. It can also be produced synthetically.

In industry, geranial is used for its lemon-like aroma in perfumery and flavorings. It is a key constituent of citral preparations and serves as an intermediate in the synthesis of other fragrance compounds.

Safety and handling: Geranial is a skin and mucous membrane irritant and may cause sensitization in some individuals. It can oxidize over time, altering its scent and potentially forming byproducts; thus it is usually stored away from light in sealed containers. It is listed as a fragrance allergen in some regulatory contexts.