[H]C1=C([H])[C@]23OC(=O)[C@](C([H])([H])[H])(C2([H])[H])C([H])([H])C([H])([H])[C@]3([H])[C@@]2(C1=C(C(=O)C([H])([H])C2([H])[H])C([H])([H])[H])C([H])([H])[H]