3'-Sulfonylesters of 2,5'-anhydro-1-(2-deoxy-beta-d-threo-pentofuranosyl)thymine as precursors for the synthesis of [(18)F]FLT: syntheses and radiofluorination trials.

Title compounds [3'-sulfonylesters of 2,5'-anhydro-1-(2-deoxy-beta-d-threo-pentofuranosyl)thymine: 2,5'-anhydro-1-(2-deoxy-3-methanesulfonyl-beta-d-threo-pentofuranosyl)thymine (1a); 2,5'-anhydro-1-(2-deoxy-3-(4-nitrobenzenesulfonyl)-beta-d-threo-pentofuranosyl)thymine (1b); 2,5'-anhydro-1(-2-deoxy-3-(toluenesulfonyl)-beta-d-threo-pentofuranosyl)thymine (1c); and 2,5'-anhydro-1(-2-deoxy-3-(2,2,2-trifluoroethanesulfonyl)-beta-d-threo-pentofuranosyl)thymine 1d] were synthesized, and their use as starting materials for the synthesis of 3'-deoxy-3'-[(18)F]fluorothymidine ([(18)F]FLT) was investigated. Radiofluorination of Compound 1b and subsequent hydrolysis with NaOH, in solution or on solid support, yielded a product with the same retention on radio thin-layer chromatography as [(18)F]FLT. However, careful analysis with high-performance liquid chromatography could not identify the product to be [(18)F]FLT.