Carbocyclic Analogues of 3′,4′-Didehydro-2′-deoxyribofuranosyl-2,4(1H,3H)-pyrimidinediones

Abstract A new method for obtaining carbocyclic analogues of 3′,4′-didehydro-2,4(1H,3H)-pyrimidinedione nucleosides in good yields consists of the reaction of the carbocyclic 2,3′-anhydronucleosides with lithium chloride in dimethylformamide. Small amounts of the carbocyclic 2′,3′-didehydro isomers are formed simultaneously. The carbocyclic 2,3′-anhydronucleosides were obtained by treating carbocyclic 5′-trityl derivatives with DAST.