11

AnnouncementsAnnouncements & Agenda& Agenda (03/09/07)(03/09/07)

Exam next Wednesday!Exam next 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 Posted!Practice Exam Posted! Review Monday @ 6:30p (Room TBA)Review Monday @ 6:30p (Room TBA) Come visit Bob!!!Come visit Bob!!!

TodayToday Quiz!Quiz! Properties & Reactions of Alcohols (12.1-12.3)Properties & Reactions of Alcohols (12.1-12.3) Ethers & Thiols (12.1-12.3)Ethers & Thiols (12.1-12.3) Aldehydes & Ketones (12.4-12.5) (?)Aldehydes & Ketones (12.4-12.5) (?)

22

One Important Example: BenzeneOne Important Example: Benzene (Know This One!) (Know This One!)

• a ring of 6 C & 6 H atoms.a ring of 6 C & 6 H atoms.• a flat ring structure drawn with three double bonds. a flat ring structure drawn with three double bonds. • represented by 2 structures because electrons are represented by 2 structures because electrons are

shared among all the C atoms.shared among all the C atoms.

Last Time: Aromatic Compounds Last Time: Aromatic Compounds “Special Conjugation”“Special Conjugation”

By the way, aromatics are called as such b/c many of By the way, aromatics are called as such b/c many of them have noticeable odors!them have noticeable odors!

33

Last Time: A color debate!Last Time: A color debate!Highly conjugated pi bonds!Highly conjugated pi bonds!

Fen+N

N N

N

H3C

CH2CH3

CH2

CH3H3C

OHOOHO

It’s the HEME in It’s the HEME in hemoglobin!!!hemoglobin!!!

Note: Highly conjugated molecules are Note: Highly conjugated molecules are typically colored!typically colored!

44

Last Time: PolymerizationLast Time: Polymerization

In polymerization, small repeating units In polymerization, small repeating units called called monomersmonomers join to form a long chain join to form a long chain polymer. polymer.

monomer unit repeats

n

55

An An alcoholalcohol contains a hydroxyl group ( contains a hydroxyl group (—OH) —OH) attached to a carbon chain.attached to a carbon chain.

• occur in many important molecules like sugars and -ol occur in many important molecules like sugars and -ol compounds (cholesterol, menthol, etc.) compounds (cholesterol, menthol, etc.)

A A phenolphenol contains a contains a hydroxyl group ( hydroxyl group (—OH) attached —OH) attached to a benzene ring.to a benzene ring.

water alcoholwater alcohol phenol phenol

Last Time: AlcoholsLast Time: Alcohols

66

Properties of AlcoholsProperties of Alcohols

• contain polar OH groups. contain polar OH groups. • form hydrogen bonds with form hydrogen bonds with

other alcohol molecules.other alcohol molecules.• Short alcohols (1-4 C Short alcohols (1-4 C

atoms) are soluble in atoms) are soluble in waterwater

• > 4 C atoms less soluble> 4 C atoms less soluble

• have much higher BPs have much higher BPs than alkanes of similar than alkanes of similar mass.mass.

77

Some Typical Alcohols (Know These)Some Typical Alcohols (Know These)

OHOH ||““rubbing alcohol”rubbing alcohol” CHCH33——CHCH——CHCH33

2-propanol (2-propanol (isopropyl alcoholisopropyl alcohol))

antifreeze antifreeze HOHO——CHCH22——CHCH22——OHOH

1,2-ethanediol (1,2-ethanediol (ethylene glycolethylene glycol)) OHOH

|| glycerolglycerol HOHO——CHCH22——CHCH——CHCH22——OHOH

1,2,3-propanetriol1,2,3-propanetriol

Could make you sickCould make you sick

Will kill youWill kill you

Part of cooking oilPart of cooking oil

88

http://www.annals.org/cgi/content/full/122/6/456http://www.annals.org/cgi/content/full/122/6/456

The Elixir Sulfanilamide disaster of 1937 The Elixir Sulfanilamide disaster of 1937

105 people died 105 people died

1938 Federal Food, Drug and Cosmetic 1938 Federal Food, Drug and Cosmetic Act, which required proof of safety before Act, which required proof of safety before the release of a new drug the release of a new drug

In the 1980s similar incident happened in In the 1980s similar incident happened in Haiti killing dozens of Haitian infantsHaiti killing dozens of Haitian infants

99

Properties of PhenolProperties of Phenol

• is soluble in water. is soluble in water.

• has a hydroxyl group that ionizes slightly has a hydroxyl group that ionizes slightly (weak acid). (weak acid).

• is corrosive and irritating to skin.is corrosive and irritating to skin.

OH O-

+ H2O + H3O+

1010

Derivatives of PhenolDerivatives of PhenolCompounds of phenol are the active ingredients in the Compounds of phenol are the active ingredients in the essential oils of cloves, vanilla, nutmeg, and mint.essential oils of cloves, vanilla, nutmeg, and mint.

1111

Drawing structures revisitedDrawing structures revisited

HC

HC

CH

CH

CH

HC

CH3CH2CH2CHCH3

OH

HC

HC

C

CH

CH

HC

OH

OH

OH

2-pentanol

Benzene

Phenol

Traditional drawing Abbreviated drawing

1212

Naming AlcoholsNaming Alcohols• IUPAC: Alcohols will be called somethingIUPAC: Alcohols will be called somethingolol• If other functional groups present, the -OH group will sometimes If other functional groups present, the -OH group will sometimes

be named as a “be named as a “hydroxylhydroxyl” group” group

FormulaFormula IUPAC IUPAC Common NameCommon Name

CHCH4 4 methanmethanee

CHCH33─OH ─OH methanmethanolol methyl alcohol methyl alcohol

CHCH33─CH─CH33 ethanethanee

CHCH33─CH─CH22─OH ─OH ethanethanolol ethyl alcohol ethyl alcohol

• Also know common names for propyl alcohol and those mentioned Also know common names for propyl alcohol and those mentioned

earlierearlier

1313

• determined by the number of alkyl groups attached to determined by the number of alkyl groups attached to the carbon bonded to the hydroxyl.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 (3ºPrimary (1º) Secondary (2º) Tertiary (3º))1 group 1 group 2 groups 2 groups 3 groups 3 groups HH CHCH33 CHCH33

|| || | |

CHCH33——CC——OH OH CHCH33——CC——OHOH CHCH33——CC——OHOH | | || | | H H H H CHCH33

Classification of AlcoholsClassification of Alcohols

1414

Reactions of AlcoholsReactions of Alcohols

1515

Combustion of AlcoholsCombustion of Alcohols

Alcohols undergo Alcohols undergo combustioncombustion with Owith O22 to produce to produce

COCO22 and H and H22O.O.

2CH2CH33OH + 3OOH + 3O22 2CO 2CO22 + 4H + 4H22O + HeatO + Heat

1616

• Alcohols Alcohols dehydratedehydrate when heated with an acid catalystwhen heated with an acid catalyst• Lose Lose —H and —OH from —H and —OH from adjacentadjacent carbon atoms carbon atoms

HH OHOH| | ||

HH——CC——CC——H H H H++, heat , heat HH——C=CC=C——H + H + HH22OO| | || | | ||

H H H H H H H H

alcoholalcohol alkenealkene

Dehydration of AlcoholsDehydration of Alcohols

1717

Learning CheckLearning Check

Write the equations for the reaction of 2-Write the equations for the reaction of 2-propanol when it undergoespropanol when it undergoes

1. combustion.1. combustion.

2. dehydration.2. dehydration.

1818

SolutionSolution

OHOH ││CHCH33─CH─CH─CH─CH3 3

= = 2-propanol 2-propanol = C= C33HH88O O

1. combustion1. combustion

2C2C33HH88O + 9OO + 9O22 6CO6CO22 + 8H + 8H22OO

2. dehydration2. dehydration OHOH │ │ HH++

CHCH33─CH─CH─CH─CH3 3 CHCH33─CH=CH─CH=CH22 + H + H22OO

Major Product: Alkene w/ Major Product: Alkene w/ more alkyl substiuentsmore alkyl substiuents

1919

When a primary alcohol is oxidized, [O],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] PrimaryPrimary alcoholalcohol AldehydeAldehyde

OOHH O O || [O] [O] ||||

CHCH33——CC——HH CH CH33——CC——H + H + HH22OO ||

HH EthanolEthanol Ethanal Ethanal (ethyl alcohol)(ethyl alcohol) (acetaldehyde) (acetaldehyde)

Oxidation of Primary (1Oxidation of Primary (1) ) AlcoholsAlcohols

This is a carbonyl This is a carbonyl group…group…

2020

Oxidation of Secondary (2Oxidation of Secondary (2) Alcohols) AlcoholsWhen a secondary alcohol is oxidized, [O],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 alcoholsecondary alcohol ketoneketone

OOHH O O ││ [O] [O] ║║

CHCH33─C─CH─C─CH33 CH CH33─C─CH─C─CH3 3 + + HH22OO

││ HH

2-propanol (isopropyl alcohol) 2-propanol (dimethyl ketone)2-propanol (isopropyl alcohol) 2-propanol (dimethyl ketone)

ASK ME ABOUT “R”!!!ASK ME ABOUT “R”!!!

2121

Oxidation of Tertiary ( 3)Oxidation of Tertiary ( 3)AlcoholsAlcohols

Tertiary 3Tertiary 3 alcohols do not readily oxidize. alcohols do not readily oxidize. [O] [O]

Tertiary alcoholTertiary alcohol no reactionno reaction OOHH

││ [O][O]

CHCH33─C─CH─C─CH33 no productno product ││

CHCH3 3 no no HH on the C-OH to oxidize on the C-OH to oxidize

2-methyl-2-propanol2-methyl-2-propanol

2222

Oxidation of Ethanol in the BodyOxidation of Ethanol in the Body

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. blood alcohol over 0.4% can be fatal.

O O O O ║ ║║ ║CHCH33CHCH22OH CHOH CH33CH CHCH CH33COH 2COCOH 2CO22 + H + H22OO

ethanol acetaldehyde ethanol acetaldehyde

acetic acidacetic acid

2323

• acts as a depressant.acts as a depressant.• kills or disables more kills or disables more

people than any other drug.people than any other drug.• is metabolized at a rate of is metabolized at a rate of

12-15 mg/dL per hour by a 12-15 mg/dL per hour by a social drinker.social drinker.

• is metabolized at a rate of is metabolized at a rate of 30 mg/dL per hour by an 30 mg/dL per hour by an alcoholic. alcoholic.

Ethanol CHEthanol CH33CHCH22OHOH

2424

Effect of Alcohol on the BodyEffect of Alcohol on the Body

2525

% Ethanol% Ethanol ProductProduct

50%50% Whiskey, rum, brandyWhiskey, rum, brandy

40%40% Flavoring extractsFlavoring extracts

15-25%15-25% Listerine, Nyquil, ScopeListerine, Nyquil, Scope

12%12% Wine, Dristan, CepacolWine, Dristan, Cepacol

3-9%3-9% Beer, LavorisBeer, Lavoris

Alcohol Contents in Common ProductsAlcohol Contents in Common Products

2626

EthersEthers• 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 has a common name that gives the alkyl names of the

attached groups followed by attached groups followed by etherether..

CHCH33─O─CH─O─CH33 CHCH33─CH─CH22─O─CH─O─CH33

dimethyl ether ethyl methyl etherdimethyl ether ethyl methyl ether

2727

Boiling Points of EthersBoiling Points of Ethers

EthersEthers• are only modestly are only modestly

polar.polar.• have an O atom, have an O atom,

but there is no H but there is no H attached. attached.

• cannot form cannot form hydrogen bonds hydrogen bonds between between etherether molecules.molecules.

2828

Solubility of Alcohols & Ethers in WaterSolubility of Alcohols & Ethers in Water

Alcohols and ethers Alcohols and ethers • are more soluble in water than alkanes because the are more soluble in water than alkanes because the

oxygen atom can hydrogen bond with water. oxygen atom can hydrogen bond with water. • with 1-4 C atoms are soluble, but not with 5 or more with 1-4 C atoms are soluble, but not with 5 or more

C atoms. C atoms.

2929

Comparing Solubility & Boiling PointsComparing Solubility & Boiling Points

Molar Boiling SolubleMolar Boiling Soluble

Compound Mass Point (°C) in Water?Compound Mass Point (°C) in Water?

AlkaneAlkane CH CH33─CH─CH22─CH─CH3 3 4444 -42-42 No No

EtherEther CH CH33─O─CH─O─CH3 3 4646 -23-23 Yes Yes

AlcoholAlcohol CH CH33─CH─CH22─OH─OH 4646 7878 Yes Yes

3030

Ethers as AnestheticsEthers as Anesthetics

Anesthetics Anesthetics • inhibit pain signals to the brain.inhibit pain signals to the brain.

• like diethyl ether CHlike diethyl ether CH33──CHCH22──OO──CHCH22──CHCH33 were used were used for over a century, but caused nausea and were for over a century, but caused nausea and were flammable.flammable.

• developed by the 1960’s were nonflammable.developed by the 1960’s were nonflammable.

Cl F F Cl F HCl F F Cl F H

│ │ ││ │ │ │ │ ││ │ │

HH──CC──CC──OO──CC──HH HH──CC──CC──OO──CC──HH

│ │ ││ │ │ │ │ ││ │ │ F F F H F HF F F H F H

Ethane(enflurane)Ethane(enflurane) Penthrane Penthrane

3131

MTBEMTBE

Methyl Methyl terttert-butyl ether -butyl ether CHCH33

││

CHCH33──OO──CC──CHCH33

││

CHCH33

• 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 use is questioned since the discovery that MTBE has contaminated water supplies.contaminated water supplies.

3232

ThiolsThiols• are carbon are carbon

compounds that compounds that contain a –SH group.contain a –SH group.

• are named in the are named in the IUPAC system by IUPAC system by adding adding thiolthiol to the to the alkane name of the alkane name of the longest carbon chain.longest carbon chain.

• the -SH group may the -SH group may also be called a also be called a ““mercaptomercapto” group” group

3333

ThiolsThiolsThiols Thiols • often have often have

strong odors.strong odors.

• are used to are used to detect gas detect gas leaks.leaks.

• are found in are found in onions, oysters, onions, oysters, and garlic.and garlic.

3434

Oxidation of ThiolsOxidation of Thiols

When thiols undergo oxidation,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 the product is a disulfidedisulfide..

[O][O]

CHCH33─S─SHH + + HHS─CHS─CH33 CH CH33─S─S─CH─S─S─CH3 3 + + HH22OO

3535

Aldehydes and KetonesAldehydes and Ketones

An An aldehydealdehyde contains a contains a carbonyl groupcarbonyl group (C=O), which (C=O), which is a carbon atom with a is a carbon atom with a double bond to an oxygen double bond to an oxygen atom.atom.

In a In a ketoneketone, , the carbon of the carbon of the the carbonyl groupcarbonyl group is is attached to two other carbon attached to two other carbon atoms.atoms.

3636

Naming AldehydesNaming Aldehydes

3737

Aldehydes in Flavorings Aldehydes in Flavorings Several naturally occurring aldehydes are Several naturally occurring aldehydes are used as flavorings for foods and fragrances.used as flavorings for foods and fragrances.

H

O

C

H

O

CCH=CH

Benzaldehyde (almonds)Benzaldehyde (almonds)

Cinnamaldehyde (cinnamon)Cinnamaldehyde (cinnamon)

3838

Naming KetonesNaming Ketones• as IUPAC, the -e in the alkane name is replaced with as IUPAC, the -e in the alkane name is replaced with

––oneone..

• With a common name, the alkyl groups attached to the With a common name, the alkyl groups attached to the carbonyl group are named alphabetically followedcarbonyl group are named alphabetically followed

by by ketone.ketone. OO OO

║ ║ ║ ║

CHCH33 ─C─CH ─C─CH33 CH CH33─C─CH─C─CH22─CH─CH33

propanonepropanone 2-butanone 2-butanone

(dimethyl ketone) (dimethyl ketone) (ethyl methyl ketone) (ethyl methyl ketone)

3939

Ketones in Common UseKetones in Common Use

Nail polish remover, solvent

Propanone, Dimethylketone, Acetone

Butter flavoring

4040

Classify each as 1) aldehyde or 2) ketone.Classify each as 1) aldehyde or 2) ketone. OO O O

|||| || ||A. CHA. CH33——CHCH22——CC——CHCH33 B. CHB. CH33——CC—H—H

CHCH3 3 O O

| | ||||C. CHC. CH33——CC——CHCH22——CC——HH D. D.

|| CHCH33

Learning CheckLearning Check

O

4141

Properties of Aldehydes & KetonesProperties of Aldehydes & Ketones• The polar carbonyl group provides dipole-dipole The polar carbonyl group provides dipole-dipole

interactions.interactions.

+ + -- + + --

C=O C=OC=O C=O

• Without an H on the oxygen, aldehydes and Without an H on the oxygen, aldehydes and ketones cannot form hydrogen bonds to each ketones cannot form hydrogen bonds to each other. other.

4242

Boiling PointsBoiling Points

Aldehydes and ketones haveAldehydes and ketones have

• polar carbonyl groups (C=O).polar carbonyl groups (C=O). + + --

C=O C=O • attractions between polar groups.attractions between polar groups. + + -- + + --

C=O C=OC=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.

4343

Comparison of Boiling PointsComparison of Boiling Points

4444

Solubility in WaterSolubility in Water

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

4545

Tollens’ TestTollens’ Test

• Tollens’ reagent,Tollens’ reagent,which contains which contains AgAg++,, oxidizes oxidizes aldehydes, but aldehydes, but not ketones.not ketones.

• AgAg+ + is reduced to is reduced to metallic Ag, metallic Ag, which appears which appears as a “mirror” in as a “mirror” in the test tube.the test tube.

4646

Benedict’s TestBenedict’s Test

• Benedict’s reagent, Benedict’s reagent, which contains Cuwhich contains Cu2+2+,,

reacts with aldehydes reacts with aldehydes that have an adjacent that have an adjacent OH group.OH group.

• An aldehyde is oxidized An aldehyde is oxidized to a carboxylic acid, to a carboxylic acid, while Cuwhile Cu2+2+ is reduced to is reduced to give red Cugive red Cu22O(s).O(s).