CC(C)=CCCC1=C2[C@H](C[C@@]3(C)[C@H]2CC[C@H]2[C@@]4(C)CCC(=O)[C@@H](C)[C@@H]4[C@H](O)C(=O)[C@@]23C)OC1=O	1,2-dihydro-6,16-O-dideacetylhelvolic acid 21,16-lactone