Methyl 7-oxo-12-propyl-amino-13-nitro-deisopropyl-dehydro-abietate

In the title compound, C(21)H(28)N(2)O(5) (systematic name: methyl 1,4a-dimethyl-7-nitro-9-oxo-6-propyl-amino-1,2,3,4,4a,9,10,10a-octa-hydro-phenanthrene-1-carboxyl-ate) the cyclo-hexane ring (A) and the central cyclo-hexene ring (B) exist at a trans ring junction, with the two methyl groups in the axial positions of the six-membered rings. Ring A has a chair conformation and ring B a half-chair conformation. An intra-molecular N-H⋯O hydrogen bond occurs. The crystal structure is stabilized by inter-molecular C-H⋯O and N-H⋯O inter-actions.