Methyl 7-oxo-12-propyl­amino-13-nitro­deisopropyl­dehydro­abietate

In the title compound, C(21)H(28)N(2)O(5) (systematic name: methyl 1,4a-dimethyl-7-nitro-9-oxo-6-propyl­amino-1,2,3,4,4a,9,10,10a-octa­hydro­phenanthrene-1-carboxyl­ate) the cyclo­hexane ring (A) and the central cyclo­hexene 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 intra­molecular N—H⋯O hydrogen bond occurs. The crystal structure is stabilized by inter­molecular C—H⋯O and N—H⋯O inter­actions.