Preparation of Esters

Chapter 21. Carboxylic Acid Derivatives: Esters and AmidesDisusun oleh :

Khoirul Haniin125090207111010Fitriana Dewi Kurniawati125090207111011Mila Fatuzzahroh125090207111023Ryzki Martha Anjani105090201111010

Based on McMurrys Organic Chemistry, 7th editionPreparation of Esters[1]Esters are usually prepared from carboxylic acids2

Ester from carboxylic acid with alkyl halide [2]3

Acid catalysist esterification : carboxylic acid with alcohol [3]

4Conversion of An Acyl Chloride Into An Ester [2]

Asam asetatAsetil Klorida5

Conversion of An Acyl Chloride Into An Ester [2]Metil AsetatAsetil Klorida6Reactions of Esters [1]Less reactive toward nucleophiles than are acid chlorides or anhydrides

Cyclic esters are called lactones and react similarly to acyclic esters 78Hydrolysis: Conversion of Esters into Carboxylic Acids [1]An ester is hydrolyzed by aqueous base or aqueous acid to yield a carboxylic acid plus an alcohol

8Mechanism of Ester Hydrolysis [1]Hydroxide catalysis via an addition intermediate

9

Conversion of metyl acetate into acetic acid [3]Metil AsetatAsam asetat1011Aminolysis of Esters [1]Ammonia reacts with esters to form amides

11Mechanism of Ester Aminolysis [2]

12

Mechanism of Reaction 1314Reduction: Conversion of Esters into Alcohols [1]Reaction with LiAlH4 yields primary alcohols

14Mechanism of Reaction 115

Mechanism of Reaction 2

16Mechanism of Reduction of Esters [1]Hydride ion adds to the carbonyl group, followed by elimination of alkoxide ion to yield an aldehydeReduction of the aldehyde gives the primary alcohol

17

Conversion of methyl propionate into propanol [3]1819Reaction of Esters with Grignard Reagents [1]React with 2 equivalents of a Grignard reagent to yield a tertiary alcohol

19Mechanism of Reaction

20Conversion of an ester into a tertiary alcohol [3]

2121.7 Chemistry of Amides [1]Amides are abundant in all living organismsproteins, nucleic acids, and other pharmaceuticals have amid functional groups

22Preparation of Amides [1]Prepared by reaction of an acid chloride with ammonia, monosubstituted amines, or disubstituted amines

23Mechanism Reaction 1[2]

24Mechanism Reaction 2[2]

25Mechanism Reaction 3[2]

26Reactions of Amides [1]Heating in either aqueous acid or aqueous base produces a carboxylic acid and amineAcidic hydrolysis by nucleophilic addition of water to the protonated amide, followed by loss of ammonia

2728Basic Hydrolysis of Amides [1]Addition of hydroxide and loss of amide ion

28Mechanism for acid-catalyzed hydrolysis of an amide [3]29

Reduction: Conversion of Amides into Amines [1]Reduced by LiAlH4 to an amine rather than an alcoholConverts C=O CH2

30 Mechanism of Reduction [1]Addition of hydride to carbonyl groupLoss of the oxygen as an aluminate anion to give an iminium ion intermediate which is reduced to the amine

31

Conversion of amide into amine [3]32Mechanism for the reaction of an N-subtituted amide with hydride ion [3]33

34Conversion of amide into amine [3]Reference[1] McMurry, J., 2008, Organic Chemistry, Seventh Edition, Thomson Learning, Inc., USA[2] Hart, H., Leslie E.C., David J.H., 2003,Kimia Organik : Suatu Kuliah Singkat, Edisi Kesebelas, diterjemahkan oleh : Suminar S.A., Penerbit Erlangga, Jakarta[3]Bruice, P.Y., 2004, Organic Chemistry, Fourth Edition, Pearson Prentice Hall, New Jersey35