We report the synthesis of five radiotracers incorporating different oxyamine spacers between hypoxia-reactive 2-nitroimidazole moiety and 5-[18F]-fluorodeoxyribose ([18F]FDR, 12) prosthetic group: three linear alkyl chains with 3, 5, 7 carbon atoms (15 a–c), a cyclopropyl ring d) 1,4-disubstituted-1,2,3-triazole e). Experiments in hypoxic cells showed that 15 d displays superior uptake kinetic...