CCOC(=O)c1ccc(-c2c(C(=O)OCC)oc3cc(O)c(CC)cc3c2=O)o1
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?