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Chapter 12 Organic Compounds with Oxygen and Sulfur 1 12.1 Alcohols, Phenols, Thiols, and Ethers Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Alcohols 2 An 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. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Alcohols 3 The names of alcohols • in the IUPAC system replace the -e with -ol • with common names use the name of the alkyl group followed by alcohol Formula IUPAC CH4 methane CH3─OH methanol CH3─CH3 ethane CH3─CH2─OH ethanol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Common Name methyl alcohol ethyl alcohol Copyright © 2012 by Pearson Education, Inc. Naming Alcohols 4 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming of Alcohols 5 Step 1 Name the longest carbon chain with the –OH group. Name an aromatic alcohol as a phenol. CH3CH2CH2OH propanol OH CH3CHCH2CH3 CH3 butanol OH CH3CHCH2CH2CHCH3 6 5 4 3 2 1 hexanol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming of Alcohols 6 Step 2 Number the chain starting at the end closer to the –OH. CH3CH2CH2OH 1-propanol OH CH3CHCH2CH3 CH3 2-butanol OH CH3CHCH2CH2CHCH3 6 5 4 3 2 1 2-hexanol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming of Alcohols 7 Step 3 Give the location and name of each substituent relative to the –OH group. CH3CH2CH2OH 1-propanol OH CH3CHCH2CH3 CH3 2-butanol OH CH3CHCH2CH2CHCH3 6 5 4 3 2 1 5-methyl-2-hexanol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Some Typical Alcohols 8 OH | “Rubbing alcohol” CH3—CH—CH3 2-propanol (isopropyl alcohol) Antifreeze HO—CH2—CH2—OH 1,2-ethanediol (ethylene glycol) OH | Glycerol HO—CH2—CH—CH2—OH 1,2,3-propanetriol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 9 Name the following compounds: 1. CH3—CH2—CH2—CH2—OH 2. OH CH3 | | CH3—CH—CH—CH2—CH3 OH 3. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 10 Step 1 Name the longest carbon chain with the –OH group. Name an aromatic alcohol as a phenol. 1. CH3—CH2—CH2—CH2—OH butanol OH CH3 | | 2. CH3—CH—CH—CH2—CH3 pentanol OH 3. cyclopentanol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 11 Step 2 Number the chain starting at the end closer to the –OH. 1. CH3—CH2—CH2—CH2—OH 1-butanol OH CH3 | | 2. CH3—CH—CH—CH2—CH3 2-pentanol OH 3. cyclopentanol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 12 Step 3 Give the location and name of each substituent relative to the –OH group. 1. CH3—CH2—CH2—CH2—OH 1-butanol OH CH3 | | 2. CH3—CH—CH—CH2—CH3 3-methyl-2-pentanol OH 3. cyclopentanol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Phenols in Medicine 13 Phenol is • the IUPAC name for benzene with a hydroxyl group • used in antiseptics and disinfectants OH OH OH OH OH CH2CH2CH2CH2CH2CH3 Phenol Resorcinol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition 4-Hexylresorcinol Copyright © 2012 by Pearson Education, Inc. Derivatives of Phenol 14 Compounds of phenol are the active ingredients in the essential oils of cloves, vanilla, nutmeg, and mint. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Phenols 15 Step 1 Name the longest carbon chain with the –OH group. Name an aromatic alcohol as a phenol. OH OH Cl Br phenol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition phenol Copyright © 2012 by Pearson Education, Inc. Naming Phenols 16 Step 2 Number the chain starting at the end closer to the –OH. OH OH 1 1 3 4 Cl Br phenol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition phenol Copyright © 2012 by Pearson Education, Inc. Naming Phenols 17 Step 3 Give the location and name of each substituent relative to the –OH group. OH OH 1 1 3 4 Cl Br 3-chlorophenol 4-bromophenol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 18 Write the structure of each of the following: A. 3-pentanol B. ethyl alcohol C. 4-methylphenol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 19 Write the structure of each of the following: A. 3-pentanol OH | CH3—CH2—CH—CH2—CH3 B. ethyl alcohol CH3—CH2—OH OH C. 4-methylphenol CH3 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Thiols 20 Thiols • contain sulfur • are similar to alcohols • contain a thiol (–SH) group • often have strong odors • are found in cheese, onions, garlic, and oysters • are used to detect gas leaks Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Thiols 21 Thiols are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Ethers 22 An ether • contains an –O– between two carbon groups • has a common name that gives the alkyl names of the attached groups, followed by ether CH3OCH3 CH3CH2OCH3 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 23 Write the structure of the following: A. 3-pentanol B. ethanethiol C. diethyl ether Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 24 A. 3-pentanol OH | CH3CH2CHCH2CH3 B. ethanethiol CH3CH2SH C. diethyl ether CH3CH2OCH2CH3 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Ethers as Anesthetics 25 Anesthetics • inhibit pain signals to the brain • like diethyl ether, CH3CH2OCH2CH3, were used for over a century, but caused nausea and were flammable • developed by the 1960s were nonflammable Cl F F Cl F H HCCOCH F F F Ethrane (enflurane) HCCOCH H F H Penthrane Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 12 Organic Compounds with Oxygen and Sulfur 26 12.2 Properties of Alcohols and Ethers Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Classification of Alcohols 27 Classification of alcohols is • determined by the number of alkyl groups attached to the carbon bonded to the hydroxyl • primary (1), secondary (2), or tertiary (3) Primary (1) 1 group H | CH3—C—OH | H Secondary (2) 2 groups CH3 | CH3—C—OH | H Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Tertiary (3) 3 groups CH3 | CH3—C—OH | CH3 Copyright © 2012 by Pearson Education, Inc. Learning Check 28 Classify each alcohol as primary, secondary, or tertiary. OH | A. CH3—CH—CH2—CH3 B. CH3—CH2—CH2—OH OH | C. CH3—CH2—C—CH2—CH3 | CH3 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 29 OH | A. CH3—CH—CH2—CH3 secondary B. CH3—CH2—CH2—OH primary OH | C. CH3—CH2—C—CH2—CH3 | CH3 tertiary Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solubility of Alcohols in Water 30 Alcohols • contain polar OH groups and form hydrogen bonds with other alcohol molecules • that have one to three carbons are soluble in water • solubility in water decreases with increasing number of carbons Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solubility of Ethers in Water 31 Ethers • do not have a polar OH group, but have a COC group • do not form hydrogen bonds • with less than four carbons are slightly soluble in water • with more than four carbons are not soluble in water Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solubility of Alcohols and Ethers in Water 32 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solubility of Phenols 33 Phenols • are slightly soluble in water • have an OH group that can form hydrogen bonds with water • can react with water to produce phenoxide ions • were once used as antiseptics OH O- + H2O Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition + H3O+ Copyright © 2012 by Pearson Education, Inc. Learning Check 34 Indicate whether each of the following is soluble in water and explain why. A. CH3CH2CH2CH2CH2CH2OH B. CH3OCH2CH3 C. CH3CH2OH Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 35 Indicate whether each of the following is soluble in water and explain why. A. CH3CH2CH2CH2CH2CH2OH Not soluble Alcohols with long carbon chains (nonpolar) are not soluble. B. CH3OCH2CH3 Slightly soluble Ethers with less than four carbons are only slightly soluble in water. C. CH3CH2OH Soluble Short-chain alcohols form hydrogen bonds with water. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 12 Organic Compounds with Oxygen and Sulfur 36 12.3 Reactions of Alcohols and Thiols Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Dehydration of Alcohols 37 Alcohols undergo • dehydration when heated with an acid catalyst • the loss of –H and –OH from adjacent carbon atoms, producing an alkene H OH | | H—C—C—H | | H H alcohol H+, heat H—C=C—H + H2O | | H H alkene Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Oxidation of 1 Alcohols 38 Alcohols undergo oxidation, increasing the number of carbon and oxygen bonds. Primary alcohols are oxidized to produce an aldehyde. 1 bond to O H OH | | H—C—C—H | | H H 1 alcohol 2 bonds to O oxidation H O | || H—C—C—H | H aldehyde Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Oxidation of 1 Alcohols 39 Alcohols undergo oxidation, increasing the number of carbon and oxygen bonds. Aldehydes can further oxidize to produce a carboxylic acid. 1 bond to O H O | || H—C—C—H | H aldehyde 2 bonds to O oxidation H O | || H—C—C—OH | H carboxylic acid Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Oxidation of 2 Alcohols 40 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 2 bonds to O H OH H | | | H—C—C—C—H | | | H H H H O H | || | H—C—C—C—H | | H H [O] 2 alcohol Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition ketone Copyright © 2012 by Pearson Education, Inc. Oxidation of Tertiary 3 Alcohols 41 Tertiary (3) alcohols do not readily oxidize. OH CH3CCH3 CH3 3 alcohol [O] no product no H to oxidize no reaction Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Oxidation and Reduction 42 In an oxidation, • there is an increase in the number of C–O bonds • there is a loss of H In a reduction, • there is a decrease in the number of C–O bonds • there is a gain of H Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Oxidation and Reduction 43 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Methanol Poisoning 44 Methanol • is also known as methyl alcohol • is highly toxic and found in windshield washer fluid, Sterno, and paint strippers • is rapidly absorbed and oxidized to formaldehyde and then formic acid O [O] CH3OH O [O] HCH methyl alcohol formaldehyde HCOH formic acid Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Ethanol, CH3CH2OH 45 Ethanol • acts as a depressant and kills or disables more people than any other drug • is metabolized at a rate of 12–15 mg/dL per hour by a social drinker • is metabolized at a rate of 30 mg/dL per hour by an alcoholic Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Effect of Alcohol on the Body 46 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Oxidation of Thiols 47 When thiols undergo oxidation, • an H atom is lost from each of two –SH groups • the product is a disulfide • protein in hair is cross-linked by disulfide bonds found in the amino acid cysteine Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 48 Select the product for the oxidation of OH CH3CHCH2CH3 [O] O A. CH3CH=CHCH3 B. CH3CCH2CH3 OH C. CO2 + H2O D. CH3CHCH2CH3 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 49 Select the product for the oxidation of OH [O] CH3CHCH2CH3 O The answer is B. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition CH3CCH2CH3 Copyright © 2012 by Pearson Education, Inc. Learning Check 50 Select 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 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 51 Select 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] O C. 4) || CH3—CH2—C—OH Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 52 Give the primary product for the reaction of 2-propanol when it undergoes A. oxidation B. dehydration Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 53 OH CH3CHCH3 = 2-propanol = C3H8O A. oxidation OH O 2CH3CHCH3 + 9O2 [O] CH3CCH3 + 6CO2 + 8H2O B. dehydration OH CH3CHCH3 H+, heat CH3CH=CH2 + H2O Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 12 Organic Compounds with Oxygen and Sulfur 54 12.4 Aldehydes and Ketones Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Carbonyl Group in Aldehydes and Ketones 55 A carbonyl group • consists of a carbon-oxygen polar double bond • has a very electronegative oxygen atom • has two lone pair electrons on the O atom • has partial positive charge on C and partial negative charge on O Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition O C Copyright © 2012 by Pearson Education, Inc. Carbonyl Group in Aldehydes and Ketones 56 A carbonyl group • in an aldehyde is attached to at least one H atom • in a ketone is attached to two carbon groups Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Aldehydes 57 An aldehyde • has an IUPAC name in which the -e in the alkane name is changed to -al • has a common name for the first four aldehydes that use the following prefixes: 1 carbon, form 2 carbons, acet 3 carbons, propion 4 carbons butyr followed by aldehyde Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Aldehydes 58 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Aldehydes 59 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Aldehydes 60 Give the IUPAC name for the following aldehydes: O || CH3CH2CH2CHCH | CH3 O C H Cl Cl Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Aldehydes 61 Step 1 Name the longest carbon chain containing the carbonyl group by replacing the e in the alkane name with al. O O || CH3CH2CH2CHCH | CH3 pentanal Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition C H Cl Cl benzaldehyde Copyright © 2012 by Pearson Education, Inc. Naming Aldehydes 62 Step 2 Name and number substituents by counting the carbonyl group as carbon 1. O O || CH3CH2CH2CHCH | CH3 C H Cl 2-methylpentanal Cl 3,4-dichlorobenzaldehyde Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Aldehydes in Flavorings 63 Several naturally occurring aldehydes are used as flavorings for foods and fragrances. O O C C H H vanillin HO OCH3 benzaldehyde (almonds) O C HC C H H cinnamaldehyde cinnamon Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Ketones 64 When naming the following ketones • in the IUPAC system, the -e in the alkane name is replaced with -one • with a common name, the alkyl groups attached to the carbonyl group are named alphabetically, followed by ketone O CH3 CCH3 propanone (dimethyl ketone) O CH3CCH2CH3 2-butanone (ethyl methyl ketone) Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Ketones 65 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Ketones 66 Name the following ketones using the IUPAC system. O || CH3CH2CHCH2CCH3 | CH3 O CH3 CH3 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Ketones 67 Step 1 Name the longest carbon chain that contains the carbonyl group by replacing the e in the alkane name with one. O O || CH3CH2CHCH2CCH3 | CH3 hexanone Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition CH3 CH3 pentanone Copyright © 2012 by Pearson Education, Inc. Naming Ketones 68 Step 2 Number the carbon chain starting from the end nearer the carbonyl group and indicate its location. O || CH3CH2CHCH2CCH3 | CH3 2-hexanone O CH3 CH3 pentanone Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Ketones 69 Step 3 Name and number any substituents on the carbon chain. O || CH3CH2CHCH2CCH3 | CH3 O CH3 4-methyl-2-hexanone CH3 2,3-dimethylcylcopentanone Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Ketones in Common Use 70 Acetone (propanone) is a solvent used in nail polish remover. Butanedione is the butter flavoring used in margarine. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 71 Classify each as an aldehyde or ketone. O || A. CH3—CH2—C—CH3 O || B. CH3—C—H O CH3 O | || C. CH3—C—CH2—C—H | CH3 D. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 72 Classify each as an aldehyde or ketone. O || A. CH3—CH2—C—CH3 O || B. CH3—C—H aldehyde ketone CH3 O | || C. CH3—C—CH2—C—H | CH3 aldehyde O D. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition ketone Copyright © 2012 by Pearson Education, Inc. Learning Check 73 Classify each as an aldehyde, ketone, alcohol, or ether. O A. CH3CH2CCH3 CH3 B. CH3OCH3 O C. CH3CCH2CH OH D. CH3CHCH3 CH3 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 74 Classify each as an aldehyde, ketone, alcohol, or ether. O A. CH3CH2CCH3 B. CH3OCH3 ketone CH3 O C. CH3CCH2CH CH3 ether OH D. CH3CHCH3 aldehyde Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition alcohol Copyright © 2012 by Pearson Education, Inc. Learning Check 75 Give the IUPAC name for each of the following ketones. O A. CH3CH2CH2CH2CCH3 O B. ClCH2CH2CCH3 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 76 Give the IUPAC name for each of the following ketones. Step 1 Name the longest carbon chain that contains the carbonyl group by replacing the e in the alkane name with one. O A. CH3CH2CH2CH2CCH3 pentanone O B. ClCH2CH2CCH3 butanone Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 77 Give the IUPAC name for each of the following ketones. Step 2 Name the carbon chain starting from the end nearer the carbonyl group and indicate its location. O A. CH3CH2CH2CH2CCH3 2-pentanone O B. ClCH2CH2CCH3 2-butanone Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 78 Give the IUPAC name for each of the following ketones. Step 3 Name and number any substituents on the carbon chain. O A. CH3CH2CH2CH2CCH3 2-pentanone O B. ClCH2CH2CCH3 4-chloro-2-butanone Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 79 Give the IUPAC name for the following aldehyde compounds. O || A. CH3—CH2—CH2—C—H CH3 O | || B. CH3—C—CH2—C—H | CH3 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 80 Give 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 CH3 O | || B. CH3—C—CH2—C—H | CH3 butanal butanal Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 81 Give 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 CH3 O | || B. CH3—C—CH2—C—H | CH3 butanal 3,3-dimethylbutanal Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 82 Draw the structural formulas for each: A. 4-methylpentanal B. 2,3-dichloropropanal C. 3-methyl-2-butanone Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 83 Draw the structural formulas for each: CH3 A. 4-methylpentanal CH3CHCH2CH2CH Cl B. 2,3-dichloropropanal O O ClCH2CHCH CH3 O C. 3-methyl-2-butanone CH3CHCCH3 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 12 Organic Compounds with Oxygen and Sulfur 84 12.5 Properties of Aldehydes and Ketones In 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. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Physical Properties 85 The 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. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solubility of Aldehydes and Ketones in Water 86 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solubility in Water 87 The electronegative O atom of the carbonyl group of aldehydes and ketones forms hydrogen bonds with water. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 88 Indicate whether each is soluble or insoluble in water. A. CH3—CH2—CH3 B. CH3—CH2—OH O || C. CH3—CH2—CH2—C—H O || D. CH3—C—CH3 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 89 Indicate 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 O || D. CH3—C—CH3 soluble Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Oxidation of Aldehydes 90 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. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Tollens’ Test 91 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. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Tollens’ Test 92 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Benedict’s Test 93 In Benedict’s test, Benedict’s reagent, which contains Cu2+, reacts with aldehydes that have an adjacent OH group. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Benedict’s Test 94 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. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Reduction of Aldehydes and Ketones 95 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. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 96 Write the structure and name of the organic product when each is mixed with Tollens’ reagent. A. butanal B. acetaldehyde C. ethyl methyl ketone Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 97 A. O O || Tollens’ || CH3—CH2—CH2—C—OH CH3—CH2—CH2—C—OH butanal B. O || Tollens’ CH3—C—H acetaldehyde butanoic acid O || CH3—C—OH acetic acid C. Ethyl methyl ketone + Tollens’ No reaction Ketones are not oxidized by Tollens’ reagent. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 12 Organic Compounds with Oxygen and Sulfur 98 12.6 Chiral Molecules Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Isomers 99 Molecules are structural isomers when they have the same molecular formula, but different bonding arrangements. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Stereoisomers 100 Stereoisomers 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.” Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chiral Molecules Have Handedness 101 Chiral molecules • have the same number of atoms arranged differently in space • have one or more chiral carbon atoms, each of which is bonded to four different groups • are like your hands Try to superimpose your thumbs, palms, back of hands, and little fingers. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Some Everyday Chiral and Achiral Objects 102 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chiral Carbon Atoms Are Mirror Images 103 • 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. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Achiral Structures Are Superimposable 104 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. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 105 Identify each as a chiral or an achiral compound. Cl Cl H C CH3 CH2CH3 A. H C Cl CH3 H C H Br B. C. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition CH3 Copyright © 2012 by Pearson Education, Inc. Solution 106 Identify each as a chiral or an achiral compound. Cl Cl H C CH3 H C Cl CH3 H C CH3 H Br A. B. C. chiral achiral chiral CH2CH3 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Fischer Projections 107 A Fischer projection • is a two-dimensional representation of a three-dimensional molecule • places the most oxidized group at the top • uses vertical lines in place of dashes for bonds that go back • uses horizontal lines in place of wedges for bonds that come forward Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Drawing Fischer Projections 108 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. D and L Notations 109 • By convention, the letter L is assigned to the structure with the –OH on the left. • The letter D is assigned to the structure with the –OH on the right. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 110 Indicate whether each pair is a mirror image that cannot be superimposed (enantiomers). CH2OH A. B. H H C CH3 CH2OH and CH3 C Br Br Cl Cl C CH3 and CH3 C H Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition H H H Copyright © 2012 by Pearson Education, Inc. Solution 111 Indicate whether each pair is a mirror image that cannot be superimposed (enantiomers). CH2OH A. B. H H C CH3 CH2OH and CH3 C Br Br Cl Cl C CH3 and CH3 C H Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition H Yes No H H Copyright © 2012 by Pearson Education, Inc. Concept Map – Organic Molecules with O and S 112 Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc.