Presentation on theme: "Chapter 12 Organic Compounds with Oxygen and Sulfur"— Presentation transcript:
1Chapter 12 Organic Compounds with Oxygen and Sulfur 12.1Alcohols, Phenols, Thiols, and Ethers
2AlcoholsAn alcohol contains a hydroxyl group (–OH) that replaces a hydrogen atom in a hydrocarbon. A phenol contains a hydroxyl group (–OH) attached to a benzene ring.
3Naming Alcohols The names of alcohols in the IUPAC system replace the -e with -olwith common names use the name of the alkyl group followed by alcoholFormulaIUPACCommon NameCH4methaneCH3─OHmethanolmethyl alcoholCH3─CH3ethaneCH3─CH2─OHethanolethyl alcohol
5Naming of AlcoholsStep 1 Name the longest carbon chain with the –OH group. Name an aromatic alcohol as a phenol. CH3CH2CH2OH propanol OH CH3CHCH2CH3 butanol CH3 OH CH3CHCH2CH2CHCH3 hexanol
6Naming of AlcoholsStep 2 Number the chain starting at the end closer to the –OH. CH3CH2CH2OH 1-propanol OH CH3CHCH2CH3 2-butanol CH3 OH CH3CHCH2CH2CHCH3 2-hexanol
7Naming of AlcoholsStep 3 Give the location and name of each substituent relative to the –OH group. CH3CH2CH2OH 1-propanol OH CH3CHCH2CH3 2-butanol CH3 OH CH3CHCH2CH2CHCH3 5-methyl-2-hexanol
9Learning Check Name the following compounds: 1. CH3—CH2—CH2—CH2—OH OH CH3| |2. CH3—CH—CH—CH2—CH33.
10Solution Step 1 Name the longest carbon chain with the –OH group. Name an aromatic alcohol as a phenol.1. CH3—CH2—CH2—CH2—OH butanolOH CH3| |2. CH3—CH—CH—CH2—CH pentanolcyclopentanol
11Solution Step 2 Number the chain starting at the end closer to the –OH.1. CH3—CH2—CH2—CH2—OH butanolOH CH3| |2. CH3—CH—CH—CH2—CH pentanolcyclopentanol
12Solution Step 3 Give the location and name of each substituent relative to the –OH group.1. CH3—CH2—CH2—CH2—OH butanolOH CH3| |2. CH3—CH—CH—CH2—CH methyl-2-pentanolcyclopentanol
13Phenols in Medicine Phenol is the IUPAC name for benzene with a hydroxyl groupused in antiseptics and disinfectantsPhenol Resorcinol Hexylresorcinol
14Derivatives of PhenolCompounds of phenol are the active ingredients in the essential oils of cloves, vanilla, nutmeg, and mint.
15Naming PhenolsStep 1 Name the longest carbon chain with the –OH group.Name an aromatic alcohol as a phenol.phenol phenol
16Naming PhenolsStep 2 Number the chain starting at the end closer to the–OH.phenol phenol
17Naming Phenols Step 3 Give the location and name of each substituent relative to the –OH group.3-chlorophenol bromophenol
18Learning CheckWrite the structure of each of the following: A. 3-pentanol B. ethyl alcohol C. 4-methylphenol
19Solution Write the structure of each of the following: A. 3-pentanol OH|CH3—CH2—CH—CH2—CH3B. ethyl alcohol CH3—CH2—OHC. 4-methylphenolOHC3
20Thiols Thiols contain sulfur are similar to alcohols contain a thiol (–SH) groupoften have strong odorsare found in cheese, onions, garlic, and oystersare used to detect gas leaks
21ThiolsThiols are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain.
22Ethers An ether contains an –O– between two carbon groups has a common name that gives the alkyl names of the attached groups, followed by etherCH3OCH3 CH3CH2OCH3
23Learning CheckWrite the structure of the following: A. 3-pentanol B. ethanethiol C. diethyl ether
24Solution OH | A. 3-pentanol CH3CH2CHCH2CH3 B. ethanethiol CH3CH2SHC. diethyl ether CH3CH2OCH2CH3
25Ethers as Anesthetics Anesthetics inhibit pain signals to the brain like diethyl ether, CH3CH2OCH2CH3, were used for over a century, but caused nausea and were flammabledeveloped by the 1960s were nonflammableCl F F Cl F HHCCOCH HCCOCHF F F H F HEthrane (enflurane) Penthrane
26Chapter 12 Organic Compounds with Oxygen and Sulfur 12.2 Properties of Alcohols and Ethers
27Classification of Alcohols Classification of alcohols isdetermined by the number of alkyl groups attached to the carbon bonded to the hydroxylprimary (1), secondary (2), or tertiary (3)Primary (1) Secondary (2) Tertiary (3) 1 group groups 3 groups H CH CH | | |CH3—C—OH CH3—C—OH CH3—C—OH | | | H H CH3
28Learning Check OH | A. CH3—CH—CH2—CH3 B. CH3—CH2—CH2—OH Classify each alcohol as primary, secondary, or tertiary.OH|A. CH3—CH—CH2—CH3B. CH3—CH2—CH2—OHC. CH3—CH2—C—CH2—CH3CH3
29Solution | A. CH3—CH—CH2—CH3 secondary B. CH3—CH2—CH2—OH primary C. CH3—CH2—C—CH2—CH3 tertiaryCH3
30Solubility of Alcohols in Water contain polar OH groups and form hydrogen bonds with other alcohol moleculesthat have one to three carbons are soluble in watersolubility in water decreases with increasing number of carbons
31Solubility of Ethers in Water do not have a polar OH group, but have a COC groupdo not form hydrogen bondswith less than four carbons are slightly soluble in waterwith more than four carbons are not soluble in water
33Solubility of Phenols Phenols are slightly soluble in water have an OH group that can form hydrogen bonds with watercan react with water to produce phenoxide ionswere once used as antiseptics+ H2O H3O+
34Learning CheckIndicate whether each of the following is soluble in waterand explain why.A. CH3CH2CH2CH2CH2CH2OHB. CH3OCH2CH3C. CH3CH2OH
35Solution Indicate whether each of the following is soluble in water and explain why.A. CH3CH2CH2CH2CH2CH2OH Not solubleAlcohols with long carbon chains (nonpolar) are not soluble.B. CH3OCH2CH Slightly solubleEthers with less than four carbons are only slightly soluble in water.C. CH3CH2OH SolubleShort-chain alcohols form hydrogen bonds with water.
36Chapter 12 Organic Compounds with Oxygen and Sulfur 12.3Reactions of Alcohols and Thiols
37Dehydration of Alcohols Alcohols undergodehydration when heated with an acid catalystthe loss of –H and –OH from adjacent carbon atoms, producing an alkeneH OH| | H+, heatH—C—C—H H—C=C—H + H2O| | | |H H H Halcohol alkene
38Oxidation of 1 Alcohols Alcohols undergo oxidation, increasing the number of carbon and oxygen bonds.Primary alcohols are oxidized to produce an aldehyde.1 bond to O bonds to OH OH H O| | oxidation | ||H—C—C—H H—C—C—H| | |H H H1 alcohol aldehyde
39Oxidation of 1 Alcohols Alcohols undergo oxidation, increasing the number of carbon and oxygen bonds.Aldehydes can further oxidize to produce a carboxylic acid.1 bond to O bonds to OH O H O| || oxidation | ||H—C—C—H H—C—C—OH| |H Haldehyde carboxylic acid
40Oxidation of 2 Alcohols Secondary alcohols are oxidized to produce a ketone.To indicate the process of oxidation, [O] is placed over the reaction arrow.1 bond to O bonds to OH OH H H O H| | | [O] | || |H—C—C—C—H H—C—C—C—H| | | | |H H H H H2 alcohol ketone
41Oxidation of Tertiary 3 Alcohols Tertiary (3) alcohols do not readily oxidize. OH CH3CCH3 [O] no product CH3 no H to oxidize 3 alcohol no reaction
42Oxidation and Reduction In an oxidation,there is an increase in the number of C–O bondsthere is a loss of HIn a reduction,there is a decrease in the number of C–O bondsthere is a gain of H
44Methanol Poisoning Methanol is also known as methyl alcohol is highly toxic and found in windshield washer fluid, Sterno, and paint strippersis rapidly absorbed and oxidized to formaldehyde and then formic acidO O[O] [O]CH3OH HCH HCOHmethyl alcohol formaldehyde formic acid
45Ethanol, CH3CH2OH Ethanol acts as a depressant and kills or disables more people than any other drugis metabolized at a rate of 12–15 mg/dL per hour by a social drinkeris metabolized at a rate of 30 mg/dL per hour by an alcoholic
47Oxidation of Thiols When thiols undergo oxidation, an H atom is lost from each of two –SH groupsthe product is a disulfideprotein in hair is cross-linked by disulfide bonds found in the amino acid cysteine
48Learning Check OH [O] CH3CHCH2CH3 O Select the product for the oxidation ofOH[O]CH3CHCH2CH3OA. CH3CH=CHCH B. CH3CCH2CH3C. CO2 + H2O D. CH3CHCH2CH3
49Solution OH [O] CH3CHCH2CH3 O The answer is B. CH3CCH2CH3 Select the product for the oxidation ofOH[O]CH3CHCH2CH3OThe answer is B CH3CCH2CH3
50Learning CheckSelect the product when CH3–CH2–CH2–OH undergoes each of the following reactions: [O] [O] CH3—CH2 —CH2OH B. C. 1) CH3—CH=CH2 2) CO2 + H2O O || 3) CH3—CH2—C—H O 4) CH3—CH2—C—OH
51SolutionSelect the product when CH3–CH2–CH2–OH undergoes each of the following reactions: O [O] B. 3) || CH3—CH2—CH2OH CH3—CH2—C—H [O] C. 4) || CH3—CH2—C—OH
52Learning CheckGive the primary product for the reaction of 2-propanol when it undergoes A. oxidation B. dehydration
53SolutionOH CH3CHCH3 = 2-propanol = C3H8O A. oxidation OH O [O] 2CH3CHCH3 + 9O2 CH3CCH3 + 6CO2 + 8H2O B. dehydration H+, heat CH3CHCH3 CH3CH=CH2 + H2O
54Chapter 12 Organic Compounds with Oxygen and Sulfur 12.4Aldehydes and Ketones
55Carbonyl Group in Aldehydes and Ketones A carbonyl groupconsists of a carbon-oxygen polar double bondhas a very electronegative oxygen atomhas two lone pair electrons on the O atomhas partial positive charge on C and partial negative charge on O
56Carbonyl Group in Aldehydes and Ketones A carbonyl groupin an aldehyde is attached to at least one H atomin a ketone is attached to two carbon groups
57Naming Aldehydes An aldehyde has an IUPAC name in which the -e in the alkane name is changed to -alhas a common name for the first four aldehydes that use the following prefixes:1 carbon, form2 carbons, acet3 carbons, propion4 carbons butyrfollowed by aldehyde
60Naming Aldehydes Give the IUPAC name for the following aldehydes: O || CH3CH2CH2CHCH|CH3
61Naming Aldehydes Step 1 Name the longest carbon chain containing the carbonyl group by replacing the e in thealkane name with al.O||CH3CH2CH2CHCH|CH3pentanalbenzaldehyde
62Naming Aldehydes Step 2 Name and number substituents by counting the carbonyl group as carbon 1.O||CH3CH2CH2CHCH|CH32-methylpentanal3,4-dichlorobenzaldehyde
63Aldehydes in Flavorings Several naturally occurring aldehydes are used as flavorings for foods and fragrances.
64Naming Ketones When naming the following ketones in the IUPAC system, the -e in the alkane name is replaced with -onewith a common name, the alkyl groups attached to the carbonyl group are named alphabetically, followed by ketoneO OCH3 CCH CH3CCH2CH3propanone butanone(dimethyl ketone) (ethyl methyl ketone)
66Naming KetonesName the following ketones using the IUPAC system. O || CH3CH2CHCH2CCH3 | CH3
67Naming KetonesStep 1 Name the longest carbon chain that contains the carbonyl group by replacing the e in the alkane name with one. O || CH3CH2CHCH2CCH3 | CH3 hexanonepentanone
68Naming KetonesStep 2 Number the carbon chain starting from the end nearer the carbonyl group and indicate its location. O || CH3CH2CHCH2CCH3 | CH3 2-hexanonepentanone
69Naming KetonesStep 3 Name and number any substituents on the carbon chain. O || CH3CH2CHCH2CCH3 | CH3 4-methyl-2-hexanone2,3-dimethylcylcopentanone
70Ketones in Common UseAcetone (propanone) is a solvent used in nail polish remover.Butanedione is the butter flavoring used in margarine.
71Learning CheckClassify each as an aldehyde or ketone. O O || || A. CH3—CH2—C—CH3 B. CH3—C—H CH3 O | || C. CH3—C—CH2—C—H D. | CH3
72SolutionClassify each as an aldehyde or ketone. O O || || A. CH3—CH2—C—CH3 B. CH3—C—H CH3 O | || C. CH3—C—CH2—C—H D. | CH3ketonealdehydealdehydeketone
73Learning CheckClassify each as an aldehyde, ketone, alcohol, or ether. O A. CH3CH2CCH3 B. CH3OCH3 CH3 O OH C. CH3CCH2CH D. CH3CHCH3 CH3
74SolutionClassify each as an aldehyde, ketone, alcohol, or ether. O A. CH3CH2CCH3 B. CH3OCH3 CH3 O OH C. CH3CCH2CH D. CH3CHCH3 CH3ketone etheraldehyde alcohol
75Learning CheckGive the IUPAC name for each of the following ketones. O A. CH3CH2CH2CH2CCH3 B. ClCH2CH2CCH3
76Solution Give the IUPAC name for each of the following ketones. Step 1 Name the longest carbon chain that contains thecarbonyl group by replacing the e in the alkane namewith one.OA. CH3CH2CH2CH2CCH3 pentanoneB. ClCH2CH2CCH3 butanone
77Solution Give the IUPAC name for each of the following ketones. Step 2 Name the carbon chain starting from the end nearer thecarbonyl group and indicate its location.OA. CH3CH2CH2CH2CCH3 2-pentanoneB. ClCH2CH2CCH3 2-butanone
78Solution Give the IUPAC name for each of the following ketones. Step 3 Name and number any substituents on the carbon chain.OA. CH3CH2CH2CH2CCH3 2-pentanoneB. ClCH2CH2CCH3 4-chloro-2-butanone
79Learning CheckGive the IUPAC name for the following aldehyde compounds. O || A. CH3—CH2—CH2—C—H CH3 O | || B. CH3—C—CH2—C—H | CH3
80SolutionGive the IUPAC name for the following aldehyde compounds. Step 1 Name the longest carbon chain containing the carbonyl group by replacing the e in the alkane name with al. O || A. CH3—CH2—CH2—C—H butanal CH3 O | || B. CH3—C—CH2—C—H butanal | CH3
81SolutionGive the IUPAC name for the following aldehyde compounds. Step 2 Name and number substituents by counting the carbonyl group as carbon 1. O || A. CH3—CH2—CH2—C—H butanal CH3 O | || B. CH3—C—CH2—C—H 3,3-dimethylbutanal | CH3
82Learning CheckDraw the structural formulas for each: A. 4-methylpentanal B. 2,3-dichloropropanal C. 3-methyl-2-butanone
83SolutionDraw the structural formulas for each: CH3 O A. 4-methylpentanal CH3CHCH2CH2CH Cl O B. 2,3-dichloropropanal ClCH2CHCH CH3 O C. 3-methyl-2-butanone CH3CHCCH3
84Chapter 12 Organic Compounds with Oxygen and Sulfur 12.5 Properties of Aldehydes and KetonesIn Tollens’ test, a silver mirror forms when the oxidation of an aldehyde reduces silver ion to metallic silver. The silvery surface of a mirror is formed in a similar way.
85Physical PropertiesThe polar carbonyl group provides dipole-dipole interactions. + - + - C=O C=O Because the electronegative oxygen atom forms hydrogen bonds with water molecules, aldehydes and ketones with one to four carbons are very soluble.
87Solubility in WaterThe electronegative O atom of the carbonyl group of aldehydes and ketones forms hydrogen bonds with water.
88Learning CheckIndicate whether each is soluble or insoluble in water. A. CH3—CH2—CH3 B. CH3—CH2—OH O || C. CH3—CH2—CH2—C—H D. CH3—C—CH3
89SolutionIndicate whether each is soluble or insoluble in water. A. CH3—CH2—CH3 insoluble B. CH3—CH2—OH soluble O || C. CH3—CH2—CH2—C—H soluble D. CH3—C—CH3 soluble
90Oxidation of Aldehydes Primary alcohols can be oxidized to aldehydes, which can be easily oxidized to carboxylic acids. Secondary alcohols can be oxidized to ketones, which cannot be further oxidized.
91Tollens’ Test In Tollens’ test, Tollens’ reagent, which contains Ag+, oxidizes aldehydes but not ketones.Ag+ is reduced to metallic Ag, which appears as a “mirror” in the test tube.
93Benedict’s TestIn Benedict’s test, Benedict’s reagent, which contains Cu2+, reacts with aldehydes that have an adjacent OH group.
94Benedict’s Test In Benedict’s test, an aldehyde is oxidized to a carboxylic acid, while Cu2+ is reduced to give red Cu2O(s).The blue Cu2+ in Benedict’s solution forms a brick-red solid of Cu2O in a positive test for many sugars and aldehydes with adjacent hydroxyl groups.
95Reduction of Aldehydes and Ketones Aldehydes and ketones can be reduced by sodium borohydride, NaBH4, or H2. The reduction of aldehydes and ketones decreases the number of carbon–oxygen bonds by addition of hydrogen or loss of oxygen.
96Learning CheckWrite the structure and name of the organic product when each is mixed with Tollens’ reagent. A. butanal B. acetaldehyde C. ethyl methyl ketone
97SolutionA. O O || Tollens’ || CH3—CH2—CH2—C—OH CH3—CH2—CH2—C—OH butanal butanoic acid B. O O || Tollens’ || CH3—C—H CH3—C—OH acetaldehyde acetic acid C. Ethyl methyl ketone + Tollens’ No reaction Ketones are not oxidized by Tollens’ reagent.
98Chapter 12 Organic Compounds with Oxygen and Sulfur 12.6 Chiral Molecules
99IsomersMolecules are structural isomers when they have the same molecular formula, but different bonding arrangements.
100StereoisomersStereoisomers have identical molecular formulas, but they are not structural isomers. In stereoisomers, the atoms are bonded in the same sequence but differ in the way they are arranged in space. When stereoisomers have mirror images that are different, they are said to have “handedness.”
101Chiral Molecules Have Handedness have the same number of atoms arranged differently in spacehave one or more chiral carbon atoms, each of which is bonded to four different groupsare like your handsTry to superimpose your thumbs,palms, back of hands, and little fingers.
103Chiral Carbon Atoms Are Mirror Images The mirror images of chiral compounds cannot be superimposed.When the H and I atoms are aligned, the Cl and Br atoms are on opposite sides.
104Achiral Structures Are Superimposable When the mirror image of an achiral structure is rotated, the structure can be aligned with the initial structure. Thus this mirror image is superimposable.
105Learning Check A. C H l B. C. B r Identify each as a chiral or an achiral compound.A.CH23lB.C.Br
106Solution chiral achiral chiral A. C H l B. C. B r Identify each as a chiral or an achiral compound.chiral achiral chiralA.CH23lB.C.Br
107Fischer Projections A Fischer projection is a two-dimensional representation of a three-dimensional moleculeplaces the most oxidized group at the topuses vertical lines in place of dashes for bonds that go backuses horizontal lines in place of wedges for bonds that come forward