天津大学高等有机化学分子重排.pptx

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1、I Classification of Rearrangement ReactionsMolecular Rearrangements:it refers those reactions in which the carbon skeleton or the position of functional group changed.第1页/共43页第2页/共43页Usually the rearrangement was classified by the electron property of the moving group,such as Nucleophilic rearrangem

2、ent,Electrophilic rearrangement,Radical rearrangement,etc.Nucleophilic rearrangement第3页/共43页Electrophilic rearrangementRadical rearrangement第4页/共43页II Nucleophilic Rearrangement1 Wagner-Meerwein rearrangement (Carbon cation rearrangement)第5页/共43页第6页/共43页Stable cationStable cation第7页/共43页第8页/共43页第9页/

3、共43页2 Pinacolic Rearrangement第10页/共43页The stable cation formed superiorPhenyl group move first第11页/共43页Phenyl with electron donor group move first第12页/共43页Under HNO2,the amino alcohol rearranges as that of pinacol 第13页/共43页3 -Ethandione Rearrangement第14页/共43页第15页/共43页-Ethandione with-hydrogen will p

4、roceed condensation第16页/共43页If NaOH was replaced by NaOMe or t-BuONa,-hydroxycarboxyester will be producedUsually,ethyloxy anion acts as a reduction reagent.第17页/共43页4 Beckmann RearrangementThe group opposite to hydroxy will shift第18页/共43页第19页/共43页The shift will keep the stereostructure of chiral ce

5、nter第20页/共43页5 Baeyer-Villiger Rearrangement第21页/共43页第22页/共43页Group moved as the following order:tertiary alkylarylHsecondary alkylprimary alkylmethyl第23页/共43页 The cumene hydroperoxide rearrangement is quite resemble the Baeyer-Villiger Rearrangement第24页/共43页 Important industrial reaction for manufa

6、cturing phenol and acetone 第25页/共43页III Electrophilic RearrangementElectrophilic rearrangement is not so common as nucleophilic rearrangement The transition state is:第26页/共43页1 Favorskii Rearrangement第27页/共43页Mechanism of Favorskii Rearrangement第28页/共43页For asymmetric cycloprapanone,the stable anion

7、 form dominantly第29页/共43页Different-chloroketone form same rearrangement product:第30页/共43页Intramolecular SN2 attack(structure maintaining):第31页/共43页2 Stevens RearrangementStructure maintaining第32页/共43页The sulfonium cation does the same 第33页/共43页Sommelet Rearrangement第34页/共43页第35页/共43页3 Wittig Rearrangement第36页/共43页第37页/共43页4 Fries Rearrangement第38页/共43页IV Radical Rearrangement第39页/共43页Usually the aryl,alkenyl and acetoxy can shift第40页/共43页第41页/共43页第42页/共43页谢谢您的观看！第43页/共43页