1. 1 Announcements & Agenda (03/12/07) Pick Up Quizzes Exam THIS Wednesday! Covers Ch 7, 8, 10-12 (not 12.6, on Exam 3) Covers Ch 7, 8, 10-12 (not 12.6, on Exam 3) Practice Exam & Key Posted! Practice Exam & Key Posted! Review TONIGHT @ 6:30p (Room 1019) Review TONIGHT @ 6:30p (Room 1019)Today Ethers & Thiols Ethers & Thiols Aldehydes & Ketones (12.4-12.5) Aldehydes & Ketones (12.4-12.5) Note Benedict’s Test, Tollen’s Test, & Iodoform Test will not be on Wednesday’s Exam! Note Benedict’s Test, Tollen’s Test, & Iodoform Test will not be on Wednesday’s Exam!

2. 2 determined by the number of alkyl groups directly attached to the carbon bonded to the hydroxyl.determined by the number of alkyl groups directly attached to the carbon bonded to the hydroxyl. primary (1°), secondary (2°), or tertiary(3).primary (1°), secondary (2°), or tertiary(3). Primary (1º) Secondary (2º) Tertiary (3º) 1 group 2 groups 3 groups H CH 3 CH 3 | | | Primary (1º) Secondary (2º) Tertiary (3º) 1 group 2 groups 3 groups H CH 3 CH 3 | | | CH 3 —C—OH CH 3 —C—OH CH 3 —C—OH | | | H H CH 3 CH 3 —C—OH CH 3 —C—OH CH 3 —C—OH | | | H H CH 3 Last Time: Alcohol Classification

3. 3 Alcohols dehydrate when heated with an acid catalystAlcohols dehydrate when heated with an acid catalyst Lose —H and —OH from adjacent carbon atomsLose —H and —OH from adjacent carbon atoms H OH H OH | | H—C—C—H H +, heat H—C=C—H + H 2 O | | | | H H H H H H H H alcohol alkene alcohol alkene Last Time: Dehydration of Alcohols

4. 4 When a primary alcohol is oxidized, [O], one H is removed from the –OH.one H is removed from the –OH. another H is removed from the C bonded to -OH.another H is removed from the C bonded to -OH. an aldehyde is produced.an aldehyde is produced. [O] [O] Primary alcohol Aldehyde Primary alcohol Aldehyde OH O OH O | [O] || | [O] || CH 3 —C—H CH 3 —C—H + H 2 O CH 3 —C—H CH 3 —C—H + H 2 O | | H Ethanol Ethanal Ethanol Ethanal (ethyl alcohol) (acetaldehyde) (ethyl alcohol) (acetaldehyde) Last Time: Oxidation of 1  Alcohols This is a carbonyl group… NOTE: If enough oxidant around, will go on to form carboxylic acid!

5. 5 Oxidation of Secondary (2  ) Alcohols When a secondary alcohol is oxidized, [O], one H is removed from the –OH.one H is removed from the –OH. another H is removed from the C bonded to -OH.another H is removed from the C bonded to -OH. a ketone is produced.a ketone is produced. [O] [O] secondary alcohol ketone secondary alcohol ketone OH O OH O │ [O] ║ │ [O] ║ CH 3 ─C─CH 3 CH 3 ─C─CH 3 + H 2 O CH 3 ─C─CH 3 CH 3 ─C─CH 3 + H 2 O │ H 2-propanol (isopropyl alcohol) 2-propanol (dimethyl ketone) 2-propanol (isopropyl alcohol) 2-propanol (dimethyl ketone)

6. 6 Oxidation of Tertiary ( 3)  Alcohols Tertiary 3  alcohols do not readily oxidize. [O] Tertiary alcoholno reaction OH OH │ [O] │ [O] CH 3 ─C─CH 3 no product CH 3 ─C─CH 3 no product │ CH 3 no H on the C-OH to oxidize CH 3 no H on the C-OH to oxidize 2-methyl-2-propanol

7. 7 Oxidation of Ethanol in the Body In the body, enzymes in the liver oxidize ethanol.enzymes in the liver oxidize ethanol. aldehyde product impairs coordination.aldehyde product impairs coordination. blood alcohol over 0.4% can be fatal. O Oblood alcohol over 0.4% can be fatal. O O ║ ║ ║ ║ CH 3 CH 2 OH CH 3 CH CH 3 COH 2CO 2 + H 2 O ethanol acetaldehyde acetic acid

8. 8 acts as a depressant.acts as a depressant. kills or disables more people than any other drug.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 12-15 mg/dL per hour by a social drinker. is metabolized at a rate of 30 mg/dL per hour by an alcoholic.is metabolized at a rate of 30 mg/dL per hour by an alcoholic. Ethanol CH 3 CH 2 OH

9. 9 Effect of Alcohol on the Body

10. 10 % EthanolProduct 50%Whiskey, rum, brandy 40%Flavoring extracts 15-25%Listerine, Nyquil, Scope 12%Wine, Dristan, Cepacol 3-9%Beer, Lavoris Alcohol Contents in Common Products

11. 11 Ethers contains an ─O─ between two carbon groups (R-O-R’).contains an ─O─ between two carbon groups (R-O-R’). has a common name that gives the alkyl names of the attached groups followed by ether.has a common name that gives the alkyl names of the attached groups followed by ether. CH 3 ─O─CH 3 CH 3 ─CH 2 ─O─CH 3 CH 3 ─O─CH 3 CH 3 ─CH 2 ─O─CH 3 dimethyl ether ethyl methyl ether dimethyl ether ethyl methyl ether

12. 12 Boiling Points of Ethers Ethers are only modestly polar.are only modestly polar. have an O atom, but there is no H attached.have an O atom, but there is no H attached. cannot form hydrogen bonds between ether molecules.cannot form hydrogen bonds between ether molecules.

13. 13 Solubility of Alcohols & Ethers in Water Alcohols and ethers are more soluble in water than alkanes because the oxygen atom can hydrogen bond with water.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.with 1-4 C atoms are soluble, but not with 5 or more C atoms.

14. 14 Comparing Solubility & Boiling Points Molar Boiling Soluble Molar Boiling Soluble Compound Mass Point (°C) in Water? Compound Mass Point (°C) in Water? Alkane CH 3 ─CH 2 ─CH 3 44-42 No Ether CH 3 ─O─CH 3 46-23 Yes Alcohol CH 3 ─CH 2 ─OH 4678 Yes

15. 15 Ethers as Anesthetics Anesthetics inhibit pain signals to the brain.inhibit pain signals to the brain. like diethyl ether CH 3 ─CH 2 ─O─CH 2 ─CH 3 were used for over a century, but caused nausea and were flammable.like diethyl ether CH 3 ─CH 2 ─O─CH 2 ─CH 3 were used for over a century, but caused nausea and were flammable. developed by the 1960’s were nonflammable.developed by the 1960’s were nonflammable. Cl F F Cl F H Cl F F Cl F H │ │ │ │ │ │ │ │ │ │ │ │ H─C─C─O─C─HH─C─C─O─C─H H─C─C─O─C─HH─C─C─O─C─H │ │ │ │ │ │ │ │ │ │ │ │ F F F H F H F F F H F H Ethane(enflurane) Penthrane Ethane(enflurane) Penthrane

16. 16 MTBE Methyl tert-butyl ether CH 3 CH 3 │ CH 3 ─O─C─CH 3 │ CH 3 CH 3 is second in production of organic chemicals.is second in production of organic chemicals. is an additive used to improve gasoline performance.is an additive used to improve gasoline performance. use is questioned since the discovery that MTBE has contaminated water supplies.use is questioned since the discovery that MTBE has contaminated water supplies.

17. 17 Thiols are carbon compounds that contain a –SH group.are carbon compounds that contain a –SH group. are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain.are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain. the -SH group may also be called a “mercapto” groupthe -SH group may also be called a “mercapto” group

18. 18 Thiols Thiols often have strong odors.often have strong odors. are used to detect gas leaks.are used to detect gas leaks. are found in onions, oysters, and garlic.are found in onions, oysters, and garlic.

19. 19 Oxidation of Thiols When thiols undergo oxidation, an H atom is lost from each of two –SH groups.an H atom is lost from each of two –SH groups. the product is a disulfide.the product is a disulfide. [O] [O] CH 3 ─SH + HS─CH 3 CH 3 ─S─S─CH 3 + H 2 O

20. 20 Aldehydes and Ketones An aldehyde contains a carbonyl group (C=O), which is a carbon atom with a double bond to an oxygen atom. In a ketone, the carbon of the carbonyl group is attached to two other carbon atoms.

21. 21 Naming Aldehydes

22. 22 Aldehydes in Flavorings Several naturally occurring aldehydes are used as flavorings for foods and fragrances. Benzaldehyde (almonds) Cinnamaldehyde (cinnamon)

23. 23 Naming Ketones as IUPAC, the -e in the alkane name is replaced with –one.as IUPAC, 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 followedWith a common name, the alkyl groups attached to the carbonyl group are named alphabetically followed by ketone. by ketone. O O O O ║ ║ ║ ║ CH 3 ─C─CH 3 CH 3 ─C─CH 2 ─CH 3 propanone 2-butanone (dimethyl ketone) (ethyl methyl ketone) (dimethyl ketone) (ethyl methyl ketone)

24. 24 Ketones in Common Use Nail polish remover, solvent Propanone, Dimethylketone, Acetone Butter flavoring

25. 25 Properties of Aldehydes & Ketones The polar carbonyl group provides dipole-dipole interactions.The polar carbonyl group provides dipole-dipole interactions.  +  -  +  -  +  -  +  - C=O C=O Without an H on the oxygen, aldehydes and ketones cannot form hydrogen bonds to each other.Without an H on the oxygen, aldehydes and ketones cannot form hydrogen bonds to each other.

26. 26 Boiling Points Aldehydes and ketones have polar carbonyl groups (C=O).polar carbonyl groups (C=O).  +  -  +  -C=O attractions between polar groups.attractions between polar groups.  +  -  +  -  +  -  +  - C=O C=O higher bp’s than alkanes and ethers of similar mass.higher bp’s than alkanes and ethers of similar mass. lower bp’s than alcohols of similar mass.lower bp’s than alcohols of similar mass.

27. 27 Comparison of Boiling Points

28. 28 Solubility in Water The electronegative O atom of the carbonyl group of aldehydes and ketones forms hydrogen bonds with water.

29. 29 Tollens’ Test Tollens’ reagent,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.Ag + is reduced to metallic Ag, which appears as a “mirror” in the test tube.

30. 30 Benedict’s Test Benedict’s reagent, which contains Cu 2+, reacts with aldehydes that have an adjacent OH group.Benedict’s reagent, which contains Cu 2+, reacts with aldehydes that have an adjacent OH group. An aldehyde is oxidized to a carboxylic acid, while Cu 2+ is reduced to give red Cu 2 O(s).An aldehyde is oxidized to a carboxylic acid, while Cu 2+ is reduced to give red Cu 2 O(s).