Methyl 12-bromo­dehydro­abietate

The title compound [systematic name: (1R)-methyl 6-bromo-7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octa­hydro­phen­anthrene-1-carboxyl­ate], C(21)H(29)BrO(2), was synthesized from N-bromo­succinimide and methyl dehydro­abietate, which was prepared through an esterification reaction using dehydro­abietic acid and methanol as raw materials. The three six-membered rings adopt planar (mean deviation = 0.002 Å) half-chair and chair conformations. The two cyclo­hexane rings form a trans ring junction with the two methyl groups in axial positions. The crystal structure is stabilized by weak inter­molecular C—H⋯O contacts along the b axis.