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