An asymmetric synthesis of carbocyclic orotidine 15 and its monophosphate 16 were accomplished via the key intermediate cyclopentanone 4, which was prepared from D-γ-ribonolactone in steps. None of synthesized the compounds inhibited orotidine 5′-monophosphate decarboxylase (EC 4.1.1.23) or orotate phosphoribosyltransferase (EC 2.4.2.10).