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Chapter Menu Esters Exit Click a hyperlink or folder tab to view the corresponding slides. Carboxylic acids and derivatives.

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Presentation on theme: "Chapter Menu Esters Exit Click a hyperlink or folder tab to view the corresponding slides. Carboxylic acids and derivatives."— Presentation transcript:

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2 Chapter Menu Esters Exit Click a hyperlink or folder tab to view the corresponding slides. Carboxylic acids and derivatives

3 Section 22-2 Esters Identify the functional groups that characterize esters. Draw the structures of esters. Discuss the properties and uses of esters

4 Section 22-2 Ethers (cont.) ester Oxygen and nitrogen are two of the most-common atoms found in organic functional groups.

5 Section 22-3 An ester is any organic compound with a carboxyl group in which the hydrogen in the hydroxyl group is replaced by an alkyl chain.ester

6 Structure of Esters Esters are carboxylic acid derivatives. They are formed from the reaction of a carboxylic acid with an alcohol.

7 Formation of an Ester Carboxylic acid alcoholEster Water EXAMPLE Ethanoic acidethanol (Acetic Acid) Ethyl ethanoate (Ethyl acetate) H+, heat

8 Properties of Esters Mildly polar Have pleasant aromas Found in natural foodstuffs (banana oil, pineapples, raspberries, etc.) Boil at approximately the same temperature as aldehydes or ketones of similar molecular weights Simpler ones are somewhat soluble in water

9 Naming Esters Use the alkyl portion of the alcohol as the first name. Remove the –ic acid ending of the carboxylic acid and replace it with –ate. The same naming rules apply if the common name of the carboxylic acid is used.

10 Examples of Ester Names Methyl ethanoate (methyl acetate) Propyl ethanoate (propyl acetate) Methyl benzoate Methyl m-bromobenzoate

11 You Try These!

12 Answers to You Try These! Cyclopentyl ethanoate –(cyclopentyl acetate) Ethyl cyclohexanecarboxylate Methyl p-nitrobenzoate Methyl butanoate

13 Formation of Soap - Esterification Fats and oils are triesters of the alcohol glycerol.

14 Formation of Soap - Saponification When they are hydrolyzed by saponification, the products are soaps.

15 Section 22-2 Ethers An ether is an organic compound containing an oxygen bonded to two carbon atoms.ether

16 Chapter Menu Carbonyl Compounds Exit Click a hyperlink or folder tab to view the corresponding slides.

17 Section 22-3 Carbonyl Compounds Identify the structures of carbonyl compounds, including aldehydes, ketones, carboxylic acids, esters, and amides. electronegative: indicates the relative ability of an element’s atoms to attract electrons in a chemical bond Discuss the properties of compounds containing the carbonyl group.

18 Carbonyl Compounds (cont.) carbonyl group aldehyde ketone carboxylic acid Carbonyl compounds contain a double- bonded oxygen in the functional group. carboxyl group ester amide condensation reaction

19 Carbonyl compounds include aldehydes, ketones, carboxylic acids, and esters The carbonyl group An aldehyde A ketone A carboxylic acids A carboxylate ester

20 Section 22-3 Organic Compounds Containing the Carbonyl Group An oxygen atom double-bonded to a carbon atom is a carbonyl group.carbonyl group Aldehydes are organic compounds in which the carbonyl group is located at the end of the carbon chain and is bonded to a carbon atom on one side and a hydrogen on the other side.Aldehydes Aldehydes are named with the suffix –al.

21 Section 22-3 Organic Compounds Containing the Carbonyl Group (cont.)

22 Section 22-3 Organic Compounds Containing the Carbonyl Group (cont.) A ketone is an organic compound in which the carbon of the carbonyl group is bonded to two other carbon atoms.ketone Ketones are named by changing the –e at the end of the alkane name to –one, and including a number before the name to indicate the position of the ketone group. Ketones and aldehydes share many chemical and physical properties because their structures are similar.

23 Section 22-3 Organic Compounds Containing the Carbonyl Group (cont.) Ketones are popular solvents for moderately polar substances. Ketones are somewhat soluble in water.

24 Section 22-3 Organic Compounds Containing the Carbonyl Group (cont.)

25 Section 22-3 Carboxylic Acids Carboxylic acids are organic compounds that have a carboxyl group.Carboxylic acids Carboxyl groups are carbonyls bonded to a hydroxyl groupCarboxyl groups Carboxylic acids are named by changing the –ane to –anoic acid.

26 Structure of Carboxylic Acids  The carboxyl group is shown in red and may be written in the condensed form: -COOH.  The term carboxylic is taken from the terms carbonyl and hydroxyl, the two structures that make up the carboxyl group.

27 Properties of Carboxylic Acids Very polar compounds Can hydrogen bond to one another and to water Boil at higher temperatures than aldehydes, ketones, or alcohols Smaller carboxylic acids are soluble in water Lower molecular weight acids have sharp, sour tastes and unpleasant aromas Longer chain carboxylic acids are called fatty acids and are important components of biological membranes

28 Naming Carboxylic Acids - IUPAC Determine the name of the parent compound, the longest continuous chain containing the carboxyl group. Replace the –e ending with the suffix –oic acid. If there are two carboxyl groups, the suffix is –dioic acid. Number the chain so the carboxyl carbon is number 1. Name and number substituents.

29 Naming carboxylic acids of cycloalkanes Add the suffix carboxylic acid to the name of the cycloalkane or substituted cycloalkane. The carboxyl group is always numbered 1. Other substituents are named and numbered as usual. Cyclopentanecarboxylic acid

30 Name the following.

31 2,4-dimethylpentanoic acid 3-methylcyclohexanecarboxylic acid 2-ethylcyclopentanecarboxylic acid 2,4-dichlorobutanoic acid

32 Common Carboxylic Acids NameStructureSource Formic acidHCOOHAnts Acetic acidCH 3 COOHVinegar Propionic acidCH 3 CH 2 COOHSwiss Cheese Butyric acidCH 3 (CH 2 ) 2 COOHRancid butter Stearic acidCH 3 (CH 2 ) 16 COOHBeef fat

33 Draw structures for the following. 2,3-dihydroxybutanoic acid 2-bromo-3-chloro-4-methylhexanoic acid 1,4-cyclohexanedicarboxylic acid 4-hydroxycyclohexanecarboxylic acid Formic acid Acetic acid

34 Naming Aromatic Carboxylic Acids These are usually named as derivatives of benzoic acid. Generally, the –oic acid or –ic acid suffix is attached to the appropriate prefix. o-bromobenzoic acid

35 Naming Aromatic Carboxylic Acids Often, the phenyl group is treated as a substituent. 2-phenylethanoic acid4-phenylpentanoic acid

36 Draw structures for the following. 2,4,6-tribromobenzoic acid 2,2,2-triphenylethanoic acid 3-phenylhexanoic acid 3-phenylcyclohexanecarboxylic acid

37 Carboxylic acid - ACID Carboxylic acids act as acids because they are proton (H+) donors. They are weak acids that dissociate to form a carboxylate ion and a hydrogen ion as shown: carboxylic acid carboxylate anion hydrogen ion

38 Acid/Base Reaction Since a carboxylic acid acts as an acid, it will neutralize a strong base like NaOH or KOH to form water and the salt of the carboxylic acid.

39 Section 22-3 Organic Compounds Derived from Carboxylic Acids (cont.) An amide group is an organic compound in which the –OH group of a carboxylic acid is replaced by a nitrogen atom bonded to other atoms.amide group

40 Section 22-3 Organic Compounds Derived from Carboxylic Acids (cont.) The amide functional group is found repeated many times in natural proteins and some synthetic materials.

41 Section 22-3 Condensation Reactions In a condensation reaction, two smaller organic molecules combine to form a more complex molecule, accompanied by the loss of a small molecule such as water.condensation reaction Condensation reactions are elimination reactions that form bonds between two atoms not previously bonded.

42 Acid Chlorides IUPAC name - Replace the –oic acid ending of the IUPAC name with –oyl chloride. Common name – Replace the –ic acid ending of the common name with –yl chloride.

43 Examples of Acid Chlorides Ethanoyl chloride (acetyl chloride) 3-bromopropanoyl chloride p-chlorobenzoyl chloride (4-chlorobenzoyl chloride)

44 Properties of Acid Chlorides Noxious, irritating chemicals Slightly polar Boil at approximately the same temperature as aldehydes or ketones of similar molecular weights React violently with water

45 Formation of Acid Chlorides Carboxylic acid Acid Chloride Ethanoic acid Ethanoyl chloride (acetic acid) (acetyl chloride)

46 Hydrolysis of Acid Chlorides Acid chloride waterCarboxylic acid Hydrochloric acid Ethanoyl chlorideethanoic acid (acetyl chloride)(acetic acid)

47 R EACTION OF C ARBONYL C OMPOUNDS WITH N UCLEOPHILES 1.One of the most important reactions of carbonyl compounds is the nucleophilic addition to the carbonyl group. 1)The carbonyl carbon bears a partial positive charge  the carbonyl group is susceptible to nucleophilic attack. 2) The electron pair of the nucleophile forms a bond to the carbonyl carbon atom. 3) The carbonyl carbon can accept this electron pair because one pair of electrons of the carbon-oxygen group double bond can shift out to the oxygen.

48 2. The carbon atom undergoes a change in its geometry and its hybridization state during the reaction. 1) It goes from a trigonal planar geometry and sp 2 hybridization to a tetrahedral geometry and sp 3 hybridization. 2) The electron pair of the nucleophile forms a bond to the carbonyl carbon atom. 3. Two important nucleophiles that add to carbonyl compounds: 1) Hydride ions form compounds such as NaBH 4 or LiAlH 4. 2) Carbanions form compounds such as RLi or RMgX. 4.Oxidation of alcohols and reduction of carbonyl compounds:

49 Oxidation-Reduction Reactions in Organic Chemistry 1.Reduction of an organic molecule usually corresponds to increasing its hydrogen content or to decreasing its oxygen content. 1)Converting a carboxylic acid to an aldehyde is a reduction: [H] stands for a reduction of the compound

50 2) Converting an aldehyde to an alcohol is a reduction: 3)Converting a n alcohol to an alkane is a reduction:

51 2.Oxidation of an organic molecule usually corresponds to increasing its oxygen content or to decreasing its hydrogen content. 1)Oxidation of an organic compound may be more broadly defined as a reaction that increases its content of any element more electronegative than carbon.

52 Alcohols by Reduction of Carbonyl Compounds 1. Primary and secondary alcohols can be synthesized by the reduction of a variety of compounds that contain the carbonyl group.

53 A.A B.B C.C D.D Section 22-3 Section 22.3 Assessment Which of the following is the carbonyl group? A.COOH B.C=O C.CONH 2 D.R-O-R′

54 A.A B.B C.C D.D Section 22-3 Section 22.3 Assessment Which of the following does NOT contain a carbonyl group? A.ketones B.esters C.amines D.aldehydes

55 A.A B.B C.C D.D Chapter Assessment 3 Which of the following does NOT contain the carbonyl group? A.ketones B.ethers C.aldehydes D.amides

56 A.A B.B C.C D.D STP 2 What type of compound does this formula represent? CH 3 CH 2 CH 2 COOH A.ester B.ether C.carboxylic acid D.ketone


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