Gonanes
Gonane
Tetracyclic hydrocarbon parent of the steroids
Gonane (cyclopentanoperhydrophenanthrene) is a chemical compound with formula C
17H
28, whose structure consists of four hydrocarbon rings fused together: three cyclohexane units and one cyclopentane. It can also be viewed as the result of fusing a cyclopentane molecule with a fully hydrogenated molecule of phenanthrene, hence the more descriptive name "perhydrocyclopenta[a]phenanthrene". The non-systematic version of the above name is "cyclopentanoperhydrophenanthrene".[1]
It has no double bonds, that is, it is completely saturated and is considered the main structure of steroids, often referred to as the steroid nucleus.[1] There are many forms of gonane, but only a few occur naturally in living organisms. Some common forms include 5α-gonane and 5β-gonane. Estrane, androstane, and pregnane are variants of gonane with additional methyl or ethyl groups attached to certain carbon positions. The term gonane is also used to describe a group of progestins that are similar to levonorgestrel but have a slightly different structure than other hormones like estranes.