[H]O[C@@]1([H])C(=O)C(=C(C([H])([H])C([H])([H])C2=C([H])OC([H])=C2[H])[C@@]2(C([H])([H])[H])C([H])([H])C([H])([H])C([H])([H])C(C([H])([H])[H])(C([H])([H])[H])[C@]12[H])C([H])([H])[H]