Crystal structure of 7-isopropyl-1,4a,N-trimethyl-1,2,3,4,4a,4b,5,6,7,8,10,10a-dodeca­hydro­phenanthrene-1-carb­ox­amide

In the title compound, C(26)H(37)NO, a new derivative of di­hydro­abietic acid, the two cyclo­hexene rings adopt half chair conformations, whereas the cyclo­hexane ring has a chair conformation. Each of the methyl groups is in an axial position with respect to the tricyclic hydro­phenanthrene residue. In the crystal packing, methyl­ene-C—H⋯π(phen­yl) inter­actions lead to supra­molecular helical chains along [010]; the amide-H atom does not form a significant inter­molecular inter­action owing to steric pressure.