CC(C)C[C@H](O)C(=O)[C@](C)(O)[C@H]1CC[C@H]2[C@@H]3CC[C@H]4CC(=O)C=C[C@]4(C)[C@H]3CC[C@@]21C 20β,23S-dihydroxycholest-1-ene-3,22-dione