The terms aldehyde and aldehydic have become an intregal part of the vocabulary of the fragrance and flavor industry. The term aldehyde was coined in 1835 by von Liebig from the term dehydrogenated alcohol (alcohol dehydrogenatus).
Chemically, the term aldehyde represents a class of organic chemicals, lying structurally between alcohols and carboxylic acids. Practically, aldehyde or aldehydic also represents a class of fragrances looked upon as classic by some and modem by others. Yet, aldhyde in each case entails a different meaning, The chemist uses it to denote any molecule with an aldehydic grouping, while the flavor and fragrance industry usually uses the term to denote the aliphatic aldehydes. The perfiumer thinks of aliphatic aldehydes as materials in the C-8 to C-12 range, while tbe flavorist uses the term to mean aliphatic aldehydes in the C-2 to C-7 range.
The first aldehydes used in our industry were mainly aromatic aldehydes. They were discovered as follows: