title: Pregnane
text: # Pregnane
  
  Pregnane, also known as 17β-ethylandrostane or as 10β,13β-dimethyl-17β-ethylgonane, is a C21 steroid and, indirectly, a parent of progesterone. It is a parent hydrocarbon for two series of steroids stemming from 5α-pregnane (originally allopregnane) and 5β-pregnane (17β-ethyletiocholane). It has a gonane core.
  
  5β-Pregnane is the parent of pregnanediones, pregnanolones, and pregnanediols, and is found largely in urine as a metabolic product of 5β-pregnane compounds.
  
  ## Pregnanes
  
  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
  
  Pregnenes have a double bond. Examples include:
  
  * Cortisone
  * Hydrocortisone
  * Progesterone
  
  ## Pregnadienes
  
  Pregnadienes have two double bonds. Examples include:
  
  * Cyproterone acetate
  * Danazol
  * Fluocinonide
  