Pregnane, also known as 17ò-ethylandrostane or as 10ò,13ò-dimethyl-17ò-ethylgonane, is a C21 steroid and, indirectly, a parent of progesterone. It is a parent hydrocarbon for two series of steroids stemming from 5ñ-pregnane (originally allopregnane) and 5ò-pregnane (17ò-ethyletiocholane). It has a gonane core.
5ò-Pregnane is the parent of pregnanediones, pregnanolones, and pregnanediols, and is found largely in urine as a metabolic product of 5ò-pregnane compounds.
Pregnanes are steroid derivatives with carbons present at positions 1 through 21.
Most biologically significant pregnane derivatives fall into one of two groups: pregnenes and pregnadienes. Another class is pregnatrienes.
Pregnenes have a double bond. Examples include:
Pregnadienes have two double bonds. Examples include: