<unk> , 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<unk> diones,<unk> lones, and<unk> diols, and is found largely in urine as a metabolic product of 5β-pregnane compounds.
Pregnane
Progestogen
Progestogen 
Norgesterone
Haloprogesterone
Progestogen ester
Ethinylestradiol
Retroprogesterone