title: Crystal structure of 7-isopropyl-1,4a,N-trimethyl-1,2,3,4,4a,4b,5,6,7,8,10,10a-dodeca-hydro-phenanthrene-1-carb-ox-amide.
abstract: In the title compound, C26H37NO, a new derivative of di-hydro-abietic acid, the two cyclo-hexene rings adopt half chair conformations, whereas the cyclo-hexane ring has a chair conformation. Each of the methyl groups is in an axial position with respect to the tricyclic hydro-phenanthrene residue. In the crystal packing, methyl-ene-C-H⋯π(phen-yl) inter-actions lead to supra-molecular helical chains along [010]; the amide-H atom does not form a significant inter-molecular inter-action owing to steric pressure.
authors.affiliation: Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Key Laboratory of Biomass Energy and Material, Jiangsu Province, National Engineering Lab. for Biomass Chemical Utilization, Key and Lab. on Forest Chemical Engineering, SFA, Nanjing, 210042, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.affiliation: Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Key Laboratory of Biomass Energy and Material, Jiangsu Province, National Engineering Lab. for Biomass Chemical Utilization, Key and Lab. on Forest Chemical Engineering, SFA, Nanjing, 210042, People's Republic of China.
authors.forename: Xin-Yan
authors.initials: XY
authors.lastname: Yan
authors.affiliation: Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Key Laboratory of Biomass Energy and Material, Jiangsu Province, National Engineering Lab. for Biomass Chemical Utilization, Key and Lab. on Forest Chemical Engineering, SFA, Nanjing, 210042, People's Republic of China.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Rao
keywords: C—H⋯π inter­actions; crystal structure; di­hydro­abietic acid derivative