Study On Synthesis Of 2-cyclopropyl-?-pyrones And 3-Sulfonyl Pyrano [3,2-c]pyrazoles

This paper mainly exploited two aspects.(1)2-diazo-3-oxo-sulfony1 derivatives with titanium enoldte sreagent and then ucleophilic addition with aldehydes,then subsequent oxidation reaction.A new research area for the ynthesis of diazo compounds was developed.A simple efficient synthesis method for heconstruction of the corestructures of 4-pyrones and 4-pyrano[3,2c]pyrazole compounds was introduced.(2)Synthesis of 2-cyclopropyl-y-pyrones and 5-cyclopropyl-2-ene-3(2H)-furanones from a polyftunctional diazo group catalyzed by a silver-ruthenium di-catalyst was studied.The reaction has good regioselectivity.The synthesis method of ?-pyrones and 3-sulfonyl pyrano[3,2-c]pyrazoles was investigated.A novel method for the synthesis of y-pyrones from 1-diazo-2,4-dioxo-5 alkyne sulfones under the catalysis of Ag(I);Synthesis of 4-pyrano[3,2-c]pyrazole derivatives from 1-diazo-2,4-dioxo-5-alkyne sulfones under the action of triethylamine has been found.This enriches the methodology of selective control of organic synthesis reactions and has a high theoretical significance.(1)The optimum.reaction conditions for synthesis of ?-pyrone derivatives were obtained:10 mol%hexafluoroantimonic acidinethanol,methanol as solvent,at room temperature.At optimal reaction conditions,the yieldis above 80%.(2)The optimal reaction conditions for synthesis of y-pyrano[3,2-c]pyrazol compounds were obtained through series of experiments:100 mol%triethylamine as base,ethanol as solvent,reflux at 50 °C.At optimal reaction conditions,the yield is above 85%.With less reaction time,high yield.Synthesis of 1-diazo-2,4-dioxo-5-alkyne sulfones(alkyne ester,phospholipids)derivatives with cyclopropanation of olefins was reviewed.In the silver ruthenium di-catalytic system,new method of the highly selective synthesis of 2-cyclopropyl-y-pyrones and 5-cyclopropyl-2-ene-3(2H)-furanones from 2-diazo-3,5-dioxo-6-yne(phospholipids sulfone)with olefins was investigated.The reaction involves the cyclization of cyclopropanation domino reaction of 6-endo-dig or 5-exo-dig.The optimum reaction conditions for synthesis of were obtained:5 mol%hexafluoroantimonic acidinethanol,5 mol%rhodium acetate,1,2-dichloroethaneas solvent,at 25 °C.At optimal reaction conditions,the yield is above 60%.The optimum reaction conditions for synthesis of were obtained:5 mol%silver acetate,5 mol%rhodium acetate,100 mol%triethylamine 1,2-dichloroethaneas solvent,at 30 °C.At optimal reaction conditions,the yield is above 44%.