C=C1C(O)[C@@H]2O[C@]3(CC[C@H](/C=C/C(C)[C@@H]4CC(C)=CC5(O[C@H](C[C@@](C)(O)C(=O)O)CCC5O)O4)O3)CC[C@H]2O[C@@H]1C(O)CC(C)[C@H]1OC2(CCCCO2)CCC1C
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?