Non-terpenoid Hydrocarbons

Essential oil constituents can be classified as terpenoids and non-terpenoid hydrocarbons. 

Non-terpenoid hydrocarbons found in essential oils such as short chain alcohols and aldehydes are formed by metabolic conversion or degradation of phospholipids and fatty acids [12]. 

Molecules with three carbon atoms can only form a straight chain however, with four carbons or more they can form both straight and branched chains. Then, their naming also changes accordingly. Isoprene is one such molecule it is chemically 2-methyl-1,3-butadiene 3 (Structure 4.2). 

---