Study On The Synthesis Of Pyrimidine Nucleoside Derivatives And 1,2-allenic Ketones

This thesis includes three chapters:In the first chapter, a novel method for the preparation of pyrone (pyridone) derivatives was developed. As an application of this methord, a series of substituted pyrone (pyridine) derivatives were obtained with good efficiency. Specific studies are as follows:1. The reaction of aromatic aldehyde with two equiv of 4-hydroxy-6-methyl-pyrone or 4-hydroxy-6-methyl-pyridone was investigated by using ionic liquid as both reaction medium and promoter. Through this reaction, a series of pyrone (pyridone) derivatives were synthesized smoothly without using any catalyst. The advantages of this method include high efficiency, good yields and simple experimental procedures.2. The condensation-cyclization cascade reaction of aromatic aldehyde with two equiv of 4-hydroxy-6-methyl-pyrone in the presence of acetic anhydride was studied by using ionic liquid as both reaction medium and promoter. Through this reaction, a series of dipyrano (dipyrido)[b]pyran derivatives were obtained. Compared with traditional methods, the procedure showed such advantages as environmentally benigncy and high efficiency.In the second chapter, a series ofα-amino phosphonates-pyrimidine nucleoside hybrids were designed and synthesized. Specific studies are as follows:1. A series ofα-aminophosphonate-pyrimidine nucleoside hybrids were synthesized via the condensation of 5-formyl-2'-deoxyuridine, aromatic amine and dimethyl phosphite under solvent-free condition.2. A series ofα-aminophosphonate-uracil hybrids were synthesized via the condensation of 5-formyluracil, aromatic amine and dimethyl phosphite under solvent-free condition. In the third chapter, a novel method for the synthesis of 1,2-allenic ketones was developed. Specific studies are as follows:A novel and efficient synthesis of 1,2-allenic ketones via RuCl3 catalyzed oxidation of homopropargyl alcohols in ionic liquid with tert-butyl hydroperoxide (TBHP) as the oxidant was developed. With this procedure, a series of 1,2-allenyl allenic ketones were prepared with moderate to good yields in an environmentally benign manner.In summary, a series of novel compounds with potential biological activities were designed and prepared in this thesis. In their preparation, several improved synthetic methodologies with simple procedure, high efficiency and environmental benigncy were developed. It is expected that these methods may find more applications in synthetic organic chemistry and related areas. In addition, some of the compounds prepared in this thesis showed moderate biological activities.