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