This disclosure relates to prodrugs of uridine diphosphate (UDP) derivatives, compositions comprising therapeutically effective amounts of those prodrugs of the UDP derivatives and methods of using those prodrugs or compositions in treating disorders that are responsive to ligands, such as agonists, of P2Y6 receptor, e.g., neuronal disorders, including neurodegenerative disorders (e.g., Alzheimer's disease, Parkinson's disease) and traumatic CNS injury, pain, Down Syndrome (DS), glaucoma, and inflammatory conditions.