Showing structure for (2e,6r)-2-methyl-6-[(1s,3r,8r,11s,12s,15r,16r)-7,7,12,16-tetramethyl-6-oxopentacyclo[9.7.0.0¹,³.0³,⁸.0¹²,¹⁶]octadecan-15-yl]hept-2-enoic acid