CPC Subgroup
C07J 71/0031 Full Title
Steroids in which the cyclopenta(a)hydrophenanthrene skeleton is condensed with a heterocyclic ring (spiro-condensed heterocyclic rings C07J21/00, C07J33/00, C07J43/00)
C07J 71/0031 Steroids in which the cyclopenta(a)hydrophenanthrene skeleton is condensed with a heterocyclic ring (spiro-condensed heterocyclic rings C07J21/00, C07J33/00, C07J43/00)