Alcohols. Copyright 2009 by Pearson Education, Inc. Copyright 2009 Pearson Education, Inc. CH 3 CH 2 CH 2 OH 1-propanol OH

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1 Chapter 12 rganic Compounds with xygen and Sulfur 12.1 Alcohols, Thiols, and Ethers Alcohols An alcohol contains a hydroxyl group ( ) attached to a carbon chain. A phenol contains a hydroxyl group ( ) attached to a benzene ring. Copyright 2009 Pearson Education, Inc. 1 2 Naming Alcohols More Names of Alcohols 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 Common Name C 4 methane methanol methyl alcohol ethane C 2 ethanol ethyl alcohol IUPAC names for longer chains number the chain from the end nearest the - group. C 2 C 2 1-propanol C C 2 2-butanol C C 2 C 2 C 5-methyl-2-hexanol Some Typical Alcohols Rubbing alcohol C 2-propanol (isopropyl alcohol) Antifreeze C 2 C 2 1,2-ethanediol (ethylene glycol) Glycerol C 2 C C 2 1,2,3-propanetriol Copyright 2009 Pearson Education, Inc. Name the following compounds. 1. C 2 C 2 C 2 2. C C C

2 Phenols in Medicine 1. C 2 C 2 C 2 1-butanol 2. C C C 2 3-methyl-2-pentanol Phenol is the IUPAC name for benzene with a hydroxyl group. is used in antiseptics and disinfectants. 3. cyclopentanol C 2 C 2 C 2 C 2 C 2 Phenol Resorcinol 4-hexylresorcinol 7 8 Derivatives of Phenol Naming Phenols Compounds of phenol are the active ingredients in the essential oils of cloves, vanilla, nutmeg, and mint. To name a phenol with two substituents, assign C-1 to the carbon attached to the. number the ring to give the lowest numbers. 1 1 Copyright 2009 Pearson Education, Inc. 3 3-chlorophenol 4 Br 4-bromophenol 9 10 Write the structure of each of the following: A. 3-pentanol Write the structure of each of the following: A. 3-pentanol C 2 C C 2 B. ethyl alcohol B. ethyl alcohol C 2 C. 4-methylphenol C. 4-methylphenol 11 12

3 assification of Alcohols assification 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 (1º) Secondary (2º) Tertiary (3º) 1 group 2 groups 3 groups C C C assify each alcohol as 1) primary, 2) secondary, or 3) tertiary. A. C C 2 B. C 2 C 2 C. C 2 C C Thiols A. C C 2 secondary B. C 2 C 2 primary C. C 2 C C 2 tertiary Thiols contain sulfur are similar to alcohols contain a thiol (-S) group often have strong odors found in cheese, onions, garlic, and oysters are used to detect gas leaks Thiols Ethers Thiols are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain. An ether contains an between two carbon groups. has a common name that gives the alkyl names of the attached groups, followed by ether. C 2 dimethyl ether ethyl methyl ether Copyright 2009 Pearson Education, Inc

4 Write the structure of the following. A. 3-pentanol B. ethanethiol A. 3-pentanol C 2 C C 2 B. ethanethiol C 2 S C. diethyl ether C. diethyl ether C 2 C Ethers as Anesthetics Anesthetics inhibit pain signals to the brain. like diethyl ether, C 2 C 2, were used for over a century, but caused nausea and were flammable. developed by the 1960s were nonflammable. F F F C C C C C C F F F F Ethrane (enflurane) Penthrane MTBE Methyl tert-butyl ether C is second in production of organic chemicals. is an additive used to improve gasoline performance. use is questioned since the discovery that MTBE has contaminated water supplies Chapter 12 rganic Compounds with xygen and Sulfur 12.2 Properties of Alcohols and Ethers Boiling Points of Alcohols Alcohols contain polar groups. form hydrogen bonds with other alcohol molecules. have higher boiling points than alkanes and ethers of similar mass. Copyright 2009 Pearson Education, Inc

5 Boiling Points of Ethers Ethers do not have a polar group. have an atom, but there is no attached. cannot form hydrogen bonds between ether molecules. Solubility of Alcohols and Ethers in Water Alcohols and ethers are more soluble in water than alkanes because the oxygen atom can hydrogen bond with water. with 1-4 C atoms are soluble, but not with 5 or more C atoms Comparing Boiling Points and Solubility Solubility of Phenol Phenol is soluble in water. has a hydroxyl group that ionizes slightly (weak acid). is corrosive and irritating to skin Indicate if each of the following is soluble in water and explain why: 1. C 2 C 2 C 2 C 2 C 2 2. C 2 3. C 2 C 2 Indicate if each of the following is soluble in water and explain why: 1. C 2 C 2 C 2 C 2 C 2 No; an alcohol with a long carbon chain (nonpolar) is not soluble. 2. C 2 Yes; an atom can hydrogen bond with water. 3. C 2 C 2 Yes; short-chain alcohols hydrogen bond with water

6 Chapter 12 rganic Compounds with xygen and Sulfur 12.3 Reactions of Alcohols and Thiols Combustion of Alcohols Alcohols undergo combustion with 2 to produce C 2 and 2. C C Energy Dehydration of Alcohols Alcohols undergo dehydration when heated with an acid catalyst. the loss of and from adjacent carbon atoms. +, heat C C C=C + 2 alcohol alkene Write the equations for the reaction of 2-propanol when it undergoes 1. combustion. 2. dehydration xidation and Reduction C = 2-propanol = C 3 8 In an oxidation, there is an increase in the number of C- bonds. there is a loss of. 1. combustion 2C C dehydration + C C=C In a reduction, there is a decrease in the number of C- bonds. there is a gain of

7 xidation and Reduction xidation of Primary (1 ) Alcohols Copyright 2009 Pearson Education, Inc. When a primary alcohol is oxidized, [], one is removed from the. another is removed from the carbon bonded to the. an aldehyde is produced. [] Primary alcohol Aldehyde [] C C + 2 Ethanol Ethanal (ethyl alcohol) (acetaldehyde) xidation of Secondary (2 ) Alcohols When a secondary alcohol is oxidized, [], one is removed from the. another is removed from the carbon bonded to the. a ketone is produced. [] secondary alcohol ketone [] C C propanol (isopropyl alcohol) 2-propanol (dimethyl ketone) xidation of Tertiary (3 ) Alcohols Tertiary (3 ) alcohols do not readily oxidize. [] Tertiary alcohol no reaction [] C no product no to oxidize 2-methyl-2-propanol xidation of Ethanol in the Body Ethanol, C 2 In the body, enzymes in the liver oxidize ethanol. the aldehyde produced impairs coordination. blood alcohol over 0.4% can be fatal. C 2 C C 2C Ethyl alcohol Acetaldehyde Acetic acid Ethanol acts as a depressant. kills or disables more people than any other drug. is metabolized at a rate of mg/dl per hour by a social drinker. is metabolized at a rate of 30 mg/dl per hour by an alcoholic. Copyright 2009 Pearson Education, Inc

8 Effect of Alcohol on the Body Alcohol Contents in Common Products % Ethanol Product 50% Whiskey, rum, brandy 40% Flavoring extracts 15-25% Listerine TM, Scope TM 20% Formula 44D TM 12% Wine, Dristan TM 10% Nyquil TM, Cepacol TM 3-9% Beer, Lavoris TM xidation of Thiols When thiols undergo oxidation, an atom is lost from each of two S groups. the product is a disulfide. [] S + S S S + 2 Select the product for the oxidation of [] C C 2 1) C=C 2) C C 2 3) C ) C C Select the product for the oxidation of [] C C 2 2) C C 2 Select the product when C 2 C 2 undergoes each of the following reactions: +, heat [] A) B) C) + 2 1) C=C 2 2) C ) C 2 C 47 48

9 A. +, heat 1) C=C 2 [] B. 3) C 2 C Chapter 12 rganic Compounds with xygen and Sulfur 12.4 Aldehydes and Ketones C ) C Carbonyl Group in Aldehydes and Ketones A carbonyl group in an aldehyde is attached to at least one atom. in a ketone is attached to two carbon groups. Naming Aldehydes 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 prefixes: form (1C), acet (2C), propion (3C), and butyr (4C), followed by aldehyde. C C C 2 C Methanal Ethanal Propanal (formaldehyde) (acetaldehyde) (propionaldehyde) Naming Aldehydes Aldehydes in Flavorings Several naturally occurring aldehydes are used as flavorings for foods and fragrances. C Benzaldehyde (almonds) C=C C Cinnamaldehyde (cinnamon) 53 54

10 Naming Ketones Ketones in Common Use In naming 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. C C C 2 Propanone 2-butanone (dimethyl ketone) (ethyl methyl ketone) Nail polish remover, solvent Propanone, dimethylketone, acetone Butter flavoring assify each as 1) aldehyde or 2) ketone. A. C 2 C B. C C. C C 2 C D. A. (2) ketone B. (1) aldehyde C. (1) aldehyde D. (2) ketone assify each as an 1) aldehyde, 2) ketone, 3) alcohol, or 4) ether. A. C 2 C B. C. C C 2 C D. C A. C 2 C B. 2) ketone 4) ether C. C C 2 C D. C 1) aldehyde 3) alcohol 59 60

11 Name each of the following: 1. C 2 C 2 C 2 C 2. C 2 C 2 C 3. C 2 C Name each of the following: 1. C 2 C 2 C 2 C pentanal 2. C 2 C 2 C 3-chloropropanal 3. C 2 C 2-butanone; ethyl methyl ketone Name the following compounds: A. C 2 C 2 C B. C. C C 2 C A. 2-pentanone; methyl propyl ketone B. cyclohexanone C. 3,3-dimethylbutanal Draw the structural formulas for each: A. 4-methylpentanal B. 2,3-dichloropropanal C. 3-methyl-2-butanone Draw the structural formulas for each: A. 4-methylpentanal C C 2 C 2 C B. 2,3-dichloropropanal C 2 C C C. 3-methyl-2-butanone C C 65 66

12 Chapter 12 rganic Compounds with xygen and Sulfur 12.5 Properties of Aldehydes and Ketones Physical Properties The polar carbonyl group provides dipole-dipole interactions. δ+ δ- δ+ δ- C= C= Without an on the oxygen, aldehydes and ketones cannot form hydrogen bonds Boiling Points Comparison of Boiling Points Aldehydes and ketones have polar carbonyl groups (C=). δ+ δ- C= attractions between polar groups. δ+ δ- δ+ δ- C= C= higher boiling points than alkanes and ethers of similar mass. lower boiling points than alcohols of similar mass Solubility in Water The electronegative atom of the carbonyl group of aldehydes and ketones forms hydrogen bonds with water. Indicate if each is soluble or insoluble in water. A. C 2 B. C 2 C. C 2 C 2 C D. C 71 72

13 Tollens Test Indicate if each is soluble or insoluble in water. A. C 2 insoluble B. C 2 soluble C. C 2 C 2 C soluble D. C soluble 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 Benedict s Test In Benedict s test, Benedict s reagent, which contains Cu 2+, reacts with aldehydes that have an adjacent group. an aldehyde is oxidized to a carboxylic acid, while Cu 2+ is reduced to give red Cu 2 (s). Write the structure and name of the organic product when each is mixed with Tollens reagent. A. Butanal B. Acetaldehyde C. Ethyl methyl ketone A. Butanal C 2 C 2 C Butanoic acid Chapter 12 rganic Compounds with xygen and Sulfur 12.6 Chiral Molecules B. Acetaldehyde C Acetic acid C. Ethyl methyl ketone None. Ketones are not oxidized by Tollen s reagent

14 Chiral bjects Some Everyday Chiral and Achiral bjects Chiral objects 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 Mirror Images The mirror images of chiral compounds cannot be superimposed. When the and I atoms are aligned, the and Br atoms are on opposite sides. Achiral 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 Identify each as a chiral or an achiral compound. Identify each as a chiral or an achiral compound. C C 2 C C Br C C 2 C C Br A. B. C. A. B. C. chiral achiral chiral 83 84

15 Fischer Projections Drawing Fischer Projections A Fischer projection is a 2-dimensional representation of a 3-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 D and L Notations By convention, the letter L is assigned to the structure with the on the left. The letter D is assigned to the structure with the on the right. Indicate whether each pair is a mirror image that cannot be superimposed (enantiomers). A. C 2 C Br and C 2 C Br B. C and C Indicate whether each pair is a mirror image that cannot be superimposed (enantiomers). A. C 2 C Br and C 2 C Br Yes No B. C and C 89