(4aS.6aR.6bS.12aS.14aR.14bR)-methyl 2.2.6a.6b.9.9.12a-heptamethyl-10.14-dioxo-1.2.3.4.4a.5.6.6a.6b.7.8.8a.9.10.11.12.12a.14.14a.14b-icosahydropicene-4a-carboxylate