1,4a,7-Trimethyl-7-vinyl-1,2,3,4,4a,4b,5,6,7,9,10,10a-dodecahydrophenanthrene-1-carboxylic acid

Abstract

The title compound, pimaric acid, C20H30O2, was isolated from a mixture of resin acids. There are three rings in the structure. The two cyclo­hexane rings have classical chair conformations with trans-fused ring junctions. The cyclo­hexene ring appears as a semi-chair.