title: Methyl 7-oxo-12-propyl-amino-13-nitro-deisopropyl-dehydro-abietate.
abstract: 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.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiang-Hui
authors.initials: XH
authors.lastname: Yi
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ying-Ming
authors.initials: YM
authors.lastname: Pan