COc1ccc(C2C3=C(CC(C)(C)CC3=O)N(CC(=O)O)C3=C2C(=O)CC(C)(C)C3)cc1OC
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?