COC1=C(C)C(=O)O[C@]12C(=O)C(C)=C1CCCCN3[C@H]([C@@H]4C[C@H](C)C(=O)O4)CC[C@]132
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?