COc1ccc(COC(=O)N/N=C2/C[C@@H](O)[C@@H](O)[C@H]3[C@@H]2CC[C@@H]2C(=O)N(C[C@@H]4CCCO4)C(=O)[C@H]23)cc1
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?