Quantum Chemistry Studys On2,4,8,10-Tetracarbonyl-3,9-Dioxy Heterocyclic Spiro[5.5] Undecane

According to the process to synthesis2,4,8,10-tetracarbonyl-dioxy heterocyclic[5.5] undecane,the first step is to sythesis pentaerythrity tetraerythrity tetrabromide by t-wo-step method.Use pyridine as catalyst,pentaerythritol reacts with benzene sulfonylto form pentaerythrityl tetrabenzene solfonate.Then use polyethylene glycol ascatalystpentaerythrityl tetrabenzene solfonate reacts with sodium bromide to form pentaerythr-ityl tetrabromide.The second step is to form four Grignard reagents in tetrahydrofura-n solvent,this reaction is the reaction of pentaerythrityl tetrabromide and magnesiumchips.Add carbon dioxide to the solution and1,3-two carboxyl-2,2-two(acetoxy)propane can be produced through hydrolysis.The last step is heating the1,3-twocarboxyl-2,2-two(acetoxy)propane crystal to produce the final products:2,4,8,10-tetr-acarbonyl-dioxy heterocyclic[5.5]undecane.This project mainly uses OPT and FREQ two keywords to obtain some quantumchemical informations. Meanwhile, use Gaussian03software to draw infrared spectro-grams and1HNMR nuclear resonance images of products.Through the study of quantum chemistry on pentaerythrity tetrabromide molecula-r,the research found that the optimized pentaerythrity tetrabromide molecular hasfour spatial orientation structure,and approaches to central symmetry.The bond lengthof C-Br is2.0237.The Mulliken charge population of Br atom is0.006. So chemicalbond C-Br in pentaerythrity tetrabromide moleculecular has low bond order. Throughthe study of quantum chemistryon1,3-two carboxyl-2,2-two(acetoxy)propanemolecular,the research found that the optimized1,3-two carboxyl-2,2-two (acetoxy)propane molecular also has four spatial orientation structure,and approaches tocentral symmetry.C1,C5,C8and two carboxyl groups C14,C18atoms are in the sameplane.C1,C2,C11and two carboxyl groups C22,C26atoms are in the same plane. TheMulliken charge population of the oxygen atom on the hydroxyl groups of thecarboxyl is-0.55,the Mulliken charge population of the oxygen atom on the carbonyl of the carboxyl is-0.40.This showed that the carboxyl groups of1,3-two carboxyl-2,2-two(acetoxy)propane can form hydrogen bonds. The Mulliken charge populationof the hydrogen of carboxyls is0.39,so1,3-two carboxyl-2,2-two(acetoxy)propanehas relatively strong acid. Through the study of quantum chemistry on2,4,8,10-tetracarbonyl-3,9-dioxy heterocyclic spiro[5.5]undecane,the Mulliken charge populati-on of C14,C19,C15,C20in the molecular is0.530,so2,4,8,10-tetracarbonyl-3,9-dioxy heterocyclic spiro[5.5] undecane is a kind of lively acylation reagent.Thispaper also elaborates all reaction mechanism in the sythesis of2,4,8,10-tetracarbonyl-3,9-dioxy heterocyclicand has thermodynamic analysis for all reactions.From theresearch of reaction thermodynamics,we find the most stable complex of1,3-twodibromo-2,2-two(brooethyl)propane four Grignard reagent in stanard condition.Wealso find the reaction of four Grignard reagent and CO2has high reaction exothe-rmic.When the reaction temperature is from253K to293K,the reaction heat is from854KJ/mol to855KJ/mol.Reaction temperature should be controlled at320℃or abovein the1,3-two carboxyl-2,2-two(acetoxy)propane,s dehydration reaction to synthesis2,4,8,10-tetracarbonyl-3,9-dioxy heterocyclic spiro[5.5]undecane.and exclude thepossibility of intermole-cular dehydration.