C=C(CC[C@]12OC(C(=O)O)C(O)(C(=O)O)C(C(=O)O)(O1)C(OC(=O)/C=C/[C@@H](C)C[C@@H](C)CC)C2O)[C@@H](OC(C)=O)[C@H](C)Cc1ccccc1
The negative base-10 logarithmic of dissociation constant (pka) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?