COC(=O)C1=C[C@@H](C(=O)OC)[C@@H]2C3=C(C(=O)C2(C)C)[C@H](C)n2c(=O)n(C)c(=O)n2[C@@H]3C1
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?