Abieta-8,13(15)-diene-18-oic acid methyl ester

[1R,(+)]-1,2,3,4,4a,5,6,7,8,9,10,10aα-Dodecahydro-1,4aβ-dimethyl-7-(1-methylethylidene)-1α-phenanthrenecarboxylic acid methyl ester