Cinnamaldehyde (C9H8O) is a yellowish, oily liquid found in the bark of cinnamon trees, and is a major component of the corresponding essential oil. It has the distinct scent of cinnamon, and is used in many foods as a flavouring agent, such as confectioneries and sweets.
Cinnamaldehyde has been shown to have antimicrobial effects, and has been used to produce antimicrobial paper in conjunction with carvacrol. It is also a fungicide, insecticide, and a repellent for many animals.
It is also a key precursor and parent compound to many aroma compounds used in perfumery, such as alpha-alkyl cinnamaldehydes (shown below), and dihydrocinnamaldehyde.
Cinnamaldehyde is biosynthesised from phenylalanine through several steps:
In the laboratory, it can also be synthesised from benzaldehyde (Day 2) and acetaldehyde (ethanal) via an acid- or base-catalysed aldol condensation reaction, which produces water as a side product:
However, it is more economically efficient to produce it via extraction from cinnamon bark, which is thus the major industrial method for cinnamaldehyde production.