| The synthesis of a,(3-acetylenic ketones phosphonate derivatives and their applications in the synthesis of heterocyclics have been exploited in this paper.The mechanisms of these reactions have been proposed.In addition,the synthesis without metal catalyzed of dihydropyrano[3,2-c]pyrazol phosphonate from ?,?-acetylenic ketone phosphonate derivatives in one pot have also been studied.The thesis consists of three parts.1.Different methods for preparation of ?,?-acetylenic ketone and their application in organic synthesis have been summarized.2.The 1,2-addition reaction of titanium enolate derived from 1-diazo-2,4-dioxo-butanone phosphonate with alkynyl alhydes has been explored.The oxidative transformation of 1-diazo-2 carbonyl-4-hydroxy-5-yne-phosphonate into 1-diazo-2,4-dicarbonyl-5-yne-phosphonate has also been exploited.In addition,the regioselective reversal in the cyclization of 1-diazo-2,4-dicarbonyl-5-yne-phosphonate based solely on subtle catalyst and solvent selection has been studied.The optimized rection conditions for the formation of the desired y-pyrone phosphonate derivatives were obtained as below:AgSbF6(10 mol%)as the catalyst,methanol as solvent,room temperature.The reaction with various substrates can get corresponding y-pyrone phosphonate derivatives in about 89%?100%yield.3.The effect of base and solvents on the synthesis of and dihydropyrano[3,2-c]pyrazol phosphonate compounds from 1-diazo-2,4-dicarbonyl-5-yne-phosphonate has been explored.The optimal rection conditions were obtained as below:anhydrous methanol as solvent,30?,TEA as base.The reaction with different substrate of acetylene phosphonate compounds provided the corresponding dihydropyrano[3,2-c]pyrazol phosphonate compounds.Chemical selectivity in the reaction is good,and alkenyl,silicon and other functional groups were not involved in the reaction.A total of 90 compounds(including 90 new compounds)were synthesized.All new compounds were characterized by IR,1H-NMR,13C-NMR,MS. |
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