大二有机下chapter-11增加一个碳原子

1、Review重要的中间体，增加一个碳原子醛酮的分离提纯羰基的保护制备醇的好方法Saturated solution醛,甲基脂肪酮,C8以下环酮Chemical Properties of Aldehydes and KetonesExercise: Complete the following reactions:在氧化或和格氏试剂反应时要注意用醇保护醛酮分子中的羰基Mg, etherChemical Properties of Aldehydes and KetonesChemical Properties of Aldehydes and Ketones6) Nucleophilic Ad

2、dition of Amines (胺) and their derivatives:Chemical Properties of Aldehydes and KetonesReaction mechanism is shown as below:N-substituted ImineN-取代亚胺Primary amine 伯胺Chemical Properties of Aldehydes and KetonesYellow pptTo distinguish aldehydes and ketonesChemical Properties of Aldehydes and Ketonesp

3、H = 4-5weakly acidic pHChemical Properties of Aldehydes and Ketones7) Nucleophilic Addition of Secondary Amines (仲胺):The Formation of Enamine (烯胺) Chemical Properties of Aldehydes and KetonesChemical Properties of Aldehydes and Ketones烯胺的水解机理：Chemical Properties of Aldehydes and KetonesExercise: Com

4、plete the following reactions:Chemical Properties of Aldehydes and Ketones8) Nucleophilic Addition of Phosphorus Ylides (磷叶立德):Chemical Properties of Aldehydes and KetonesThe Wittig Reaction A ketone or aldehyde is converted into an alkene by means of the Wittig ( 1979, Nobel Prize Winner) Reaction.

5、Wittig reagentPhosphorus Ylides磷叶立德 A great many mono-, di-, and trisubstituted alkenes can be prepared from the appropriate combination of Witting reagent and aldehyde or ketone.a) Preparation of Wittig Reagent:b) Nucleophilic AdditionMechanism:Chemical Properties of Aldehydes and Ketones The real

6、value of Witting reaction is that it yields a pure alkene of known structure, and no alkene isomers are formed. Vitamin A Witting reaction are used commercially in the synthesis of numerous pharmaceutical (药物) agent.Chemical Properties of Aldehydes and KetonesChemical Properties of Aldehydes and Ket

7、onesExercise: 重要的中间体，多一个碳原子部分醛酮的分离提纯，现象？2，4-二硝基苯肼的反应，用于醛酮的鉴定，制备烯烃的好方法反应的可逆性，可在反应中对羰基进行保护Witting 反应醛、甲基脂肪酮、C8以下环酮制备醇的好方法，注意反应有加成和酸性水解两步，写完整条件通常用二元醇，乙二醇pH = 4-5 ?RLi, OrganozincH+H+RMgX -+CC HHOReactions of -HNucleophilic AdditionChemical Properties of Aldehydes and KetonesCH3CH=CH2pKa 38 25 20Enolate

8、 ion 烯醇负离子Chemical Properties of Aldehydes and Ketones2. Condensations of Aldehydes and Ketones1) The Aldol Reactions (羟醛缩合反应) When acetaldehyde is treated with a base, a rapid and reversiblecondensation occurs. The product is a -hydroxy aldehyde,or aldol (aldehyde+ alcohol).- hydroxy aldehydeP362-羟基醛Chemical Properties of Aldehydes and Ket