Nucleic acids U 0700Synthesis and Biological Evaluation of 2'-3'-Didehydro-2',3'-dideoxy-9-deazaguanosine, a Monophosphate Prodrug and Two Analogues, 2',3'-Dideoxy-9-deazaguanosine and 2',3'-Didehydro-2',3'-dideoxy-9-deazainosine. -Some analogues of the carbocyclic nucleoside Carbovir are designed: deazaguanosine (V) and its monophosphate prodrug (VI) are achieved via thionocarbonate derivative (IV). They show minimal cytotoxic activity against L1210 leukemia, CCRF-CEM lymphoblastic leukemia, and B16F10 melanoma cells and are inactive against HIV. -(LIU, M.-C.; LUO, M.-Z.; MOZDZIESZ, D. E.; DUTSCHMAN, G. E.; GULLEN, E. A.; CHENG, Y.-C.; SARTORELLI*, A. C.; Nucleosides, Nucleotides Nucleic Acids 24 (2005) 2, 135-145; Dep. Pharmacol., Yale Univ. Sch. Med., New Haven, CT 06510, USA; Eng.) -H. Hoennerscheid 12-231