Study On The Synthesis Of5-electron-deficient Alkenyl Substituted Pyrimidine Nucleoside Analogues

In this thesis, novel synthetic protocols for the preparation of5-electron-deficient alkenyl substitutedpyrimidine nucleosides have been developed. It includes the following three chapters:In the first chapter, a series of5-(2,2-dibromovinyl) substituted pyrimidine nucleosides were preparedthrough the condensation of5-formyl pyrimidine nucleosides with carbon tetrabromide.In the second chapter, a series of (E)-5-(2-bromovinyl) substituted pyrimidine nucleosides (includingthe antiviral drug, brivudine, BVDU) were synthesized through the stereoselective debromination of5-(2,2-dibromovinyl) substituted pyrimidine nucleosides. Compared with literature methods for thepreparation of BVDU, the synthetic methodology developed in this thesis has advantages such as improvedefficiency and simpler procedure.In the third chapter, a series of (E)-5-(2-nitrovinyl) substituted pyrimidine nucleosides were preparedthrough Henry reaction between5-formyl pyrimidine nucleosides with nitromethane.