CC1=C[C@H]2OC(=O)[C@@H](C)[C@H]2C[C@@H]2[C@H]1C[C@@H](O)[C@@]2(C)O
Hydrogen bond acceptor: The atom, ion, or molecule component of a hydrogen bond which does not supply the bridging (shared) hydrogen atom. How many hydrogen bond acceptors does the molecule have?