C[C@H]1OC(=O)[C@@]23[C@@H]4[C@H]5OC(=O)[C@]4(C)C[C@@H]4[C@]2(C)[C@H](C=C2C(=CC(=O)OC2(C)C)[C@@]42CO2)O[C@@]13O5	chrysogenolide A