Organic Nomenclature Organic Compounds Organic Compounds - any covalently bonded compound containing carbon (except carbonates and oxides)

Organic Nomenclature

Organic Compounds

• Organic Compounds - any covalently bonded compound containing carbon (except carbonates and oxides)

Organic Compounds

Contain carbon

Have covalent bonds

Have low melting points

Have low boiling points

Burn in air (oxygen)

Are soluble in nonpolar solvents

Form large molecules

General Characteristics of Organic Molecules

• Organic molecules exhibit three different types of hybridization at the carbon center:– sp3 hybridized carbons for tetrahedral geometries;– sp2 hybridized carbons for trigonal planar geometries; and– sp hybridized carbons for linear geometries.

Stabilities of Organic Molecules

• Carbon forms very strong bonds between H, O, N, and halogens.

• Carbon also forms strong bonds with itself.• Therefore, C can form stable long chain or ring

structures.• Bond strength increases from single to double to

triple bond.• Bond length decreases in the same direction.

Hydrocarbons

• Hydrocarbons - Organic compounds that contain only carbon & hydrogen

• Alkanes - contain only single covalent bonds• Alkenes - contain one or more carbon -

carbon double bond• Alkynes - contain one or more carbon-carbon

triple bond

Saturated & Unsaturated Hydrocarbons

• Saturated hydrocarbons – contain only single carbon-carbon bonds (alkanes)

• Unsaturated hydrocarbons – contain double carbon-carbon bonds (alkenes) or triple carbon-carbon (alkynes) bonds

Formulas

• Alkanes = CnH2n+2

• Alkenes = CnH2n

• Alkynes = CnH2n-2

Nomenclature

• Must memorize prefixes• To name, look at the

formula for the hydrocarbon

• Determine if it is an alkane, alkene, or alkyne

• Use the prefix for the number of carbons

• Add ending (ane, ene, yne)

PrefixPrefix # of # of carbon carbon atomsatoms

Meth-Meth- 11

Eth-Eth- 22

Prop-Prop- 33

But-But- 44

Pent-Pent- 55

Hex-Hex- 66

Hept-Hept- 77

Oct-Oct- 88

Non-Non- 99

Dec-Dec- 1010

Example

• Name C3H8

• This falls under the equation CnH2n+2

• Therefore it is an alkane• Since n=3 we will use the prefix prop• Since it is an alkane we will use the ending ane• propane

Alkanes

Contain C and H only

Contain single bonds C-C

Have 4 bonds to every carbon (C) atom

Are nonpolar

Complete Structural Formulas

Show the bonds between each of the atoms H H

H C H H C H H H

CH4 , methane

Drawing structures: it’s all good

On a test, choose a method that shows all Hs

CH3

CH

CH

CH3

CH3

CH3

CH3

CHCH

CH3

2-butene

This is called the “condensed structure”

C C C C

H

H

H

H H H

H

H

CH3 CH CH CH3

CH3CH=CHCH3

Using brackets can also shorten some formulas: CH3(CH2)4CH3 vs. CH3CH2CH2CH2CH2CH3

More Alkanes

H H Condensed Structural Formulas

H C C H CH3 CH3

H H Ethane

H H H

H C C C H CH3 CH2 CH3

H H H Propane

IUPAC Names

Name # carbons Structural Formula

Methane 1 CH4

Ethane 2 CH3CH3

Propane 3 CH3CH2CH3

Butane 4 CH3CH2CH2CH3

Pentane 5 CH3CH2CH2CH2CH3

Naming: common vs. IUPAC• Common names used in the 1800’s are still

used for some compounds today:

H C C HAcetylene

O

CCH3CH3

AcetoneFormic acid

C

O

OHH

• The International Union of Pure and Applied Chemistry (IUPAC) was established in 1900s

• Frequent revisions to nomenclature• Systematic method allows an infinite number

of compounds to be named given a few rules

IUPAC NAMES

Name # carbons Structural Formula

Hexane 6 CH3CH2CH2CH2CH2CH3

Heptane 7 CH3CH2CH2CH2CH2CH2CH3

Octane 8 CH3CH2CH2CH2CH2CH2CH2CH3

Nonane 9 CH3 CH2 CH2CH2CH2CH2CH2CH2CH3

Decane 10 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3

Learning Check Alk1

A. What is the condensed formula for H H H H

H C C C C H

H H H H

B. What is its molecular formula?C. What is its name?

Branched Alkanes

CH3

CH3CHCH3

methyl groups

CH3 CH3

CH3CHCH2CHCH3

Alkyl Groups

Branches on carbon chains H H C CH3 methyl H H H H C C CH3CH2 ethyl H H

Naming Branched Alkanes

CH3 methyl branch

CH3CH2CH2CHCH2CH3

6 5 4 3 2 1 Count

Naming Branched Alkanes

CH3 methyl branch

CH3CH2CH2CHCH2CH3

6 5 4 3 2 1 Count

3-Methylhexane

on third C CH3 six carbon chain group

CH3 CH3

CH3

CH3Naming side chains

• Names are made up of: side chains, root

• Root is the longest possible HC chain• Must contain multiple bonds if present• Add -yl to get name of side chain• Common side chains include:

CH3- methyl CH3CH2- ethyl

CH3CH2CH2- propyl (CH3)2CH- isopropyl

• 2,3-dimethylpentane

CH3 C H3

C H3

C H3

CH3CH

CH3

*

• “iso” (branched) is not an IUPAC convention• Br- (bromo), Cl- (chloro), F- (fluoro), I- (iodo)

ene

Naming side chainsExample: use the rules to name:

CH3 CH2 C

CH2

CH2 C

CH2

CH3

CH3

CH3

Rule 1: choose the correct ending

ene

Rule 2: longest carbon chain

Naming side chains

CH3 CH2 C

CH2

CH2 C

CH2

CH3

CH3

CH3

• Alkenes and Alkynes– Alkenes are hydrocarbons with at least one double

carbon to carbon bond.• To show the presence of the double bond, the –

ane suffix from the alkane name is changed to –ene.

– The alkenes are unsaturated with respect to hydrogen• This means it does not have the maximum

number of hydrogen atoms as it would if it were an alkane (a saturated hydrocarbon).

– Naming is similar to naming alkanes except:• The longest continuous chain must contain the

double bond.• The base name now ends in –ene.• The carbons are numbered so as to keep the

number for the double bond as low as possible.• The base name is given a number which identifies

the location of the double bond.– An alkyne is a hydrocarbon with at least one carbon

to carbon triple bond.– Naming an alkyne is similar to the alkenes, except the

base name ends in –yne.

Alkenes

Carbon-carbon double bonds Names end in -ene

H2C=CH2 ethene (ethylene)

H2C=CH-CH3 propene (propylene)

cyclohexene

Alkynes

Carbon-carbon triple bonds Names end in -yne

HCCH ethyne(acetylene)

HCC-CH3 propyne

Naming Alkenes and Alkynes

When the carbon chain has 4 or more C atoms, number the chain to give the lowest number to the double or triple bond.

1 2 3 4

CH2=CHCH2CH3 1-butene

CH3CH=CHCH3 2-butene

CH3CCCH3 2-butyne

Numbering carbonsQ- draw penteneA- Where’s the bond?

We number C atoms

• Thus, naming compounds with multiple bonds is more complex than previously indicated

• Only if 2+ possibilities exist, are #s needed• Always give double bond the lowest number• Q - Name these

C C C CCH3

H

H

H

H H H

HCH31

C2

C3

C4

C5

H

H

H

H H H

HCH35

C4

C3

C2

C1

H

H

H

H H H

H

Ethene

3-nonyne

2-buteneCH3

CH

CH

CH3

CH3 CH3

C2H4

1-pentene

Multiple multiple bonds

• Give 1st bond (1st point of difference) lowest #• include di, tri, tetra, penta, etc. before ene/yne• Comma between #s, hyphen between #-letter• You do not need to know ene + yne

2,3-heptadieneCH3CH3

CH3

CH2CCCCCCCH3

2,4,6-nonatriyne

C C C C

H

H

H

H

H

H

CH3CH2CH2CH=C=CH2

CH2CCH

CHCH2

2-butyne

1,2-hexadiene1,2,4-pentatriene

C

C

C

CC H

HHH

H

H

HH H

H

Cyclic structures

• Cyclic structures are circular• Have “cyclo” in name• Benzene is not a cyclic structure

• cyclopentaneQ- Draw these (note: carbons in a double bond

should be consecutive- 1 and 2, 5 and 6, etc.): cyclobutene 1,3-cyclopentadiene cyclopropane

1-hexene ene

Rule 3: attach prefix (according to # of C)

Naming side chains

CH3 CH2 C

CH2

CH2 C

CH2

CH3

CH3

CH3

Rule 4: Assign numbers to each carbon

1-hexene

Naming side chains

CH3 CH2 C

CH2

CH2 C

CH2

CH3

CH3

CH3

Rule 4: Assign numbers to each carbon

CH3 CH2 C2

CH21

CH23

C4

CH25

CH3

CH3

CH36

CH3 CH2 C

CH2

CH2 C

CH2

CH3

CH3

CH3

1-hexene 1-hexene

Naming side chains

CH3 CH2 C2

CH21

CH23

C4

CH25

CH3

CH3

CH36

Rule 5: Determine name for side chains

CH3 CH2 C

CH2

CH2 C

CH2

CH3

CH3

CH3

1-hexene 1-hexene

Naming side chains

ethyl

methyl

methyl

CH3 CH2 C

CH2

CH2 C

CH2

CH3

CH3

CH3

CH3 CH2 C2

CH21

CH23

C4

CH25

CH3

CH3

CH36

2-ethyl-4,4-dimethyl-1-hexene

Naming side chains

ethyl

methyl

methyl

Rule 6: attach name of branches

Learning Check HA3

Write the IUPAC name for each of the following unsaturated compounds:

A.CH3CH2CCCH3

CH3

B. CH3C=CHCH3 C.

CH3

Solutions HA3

Write the IUPAC name for each of the following unsaturated compounds:

A.CH3CH2CH=CHCH3 2-pentene

CH3

B. CH3C=CHCH3 C.

2-methyl-2-butene 3-methylcyclopentene

CH3

Numbering priority

• 1. functional groups• 2. double and triple bonds• 3. substituents

• Once all groups have been numbered, place them in alphabetical order in the final compounds name.

• Numbers are separated by commas• Names and numbers are separated by dashes.• Use mathematical prefixes for multiple

substituent's.

• Often times you will find shorter branches of carbons off of the

• longest (main or parent) chain. These branches are known as

• alkyl groups, branches or substituents.• They are named using the same prefixes as before

but using -yl• as a suffix on the name.

• Naming Branched Chain Alkanes• 1. Find the longest continuous chain of

hydrocarbon (remember• that they may bend around corners). This is

your parent chain.• 2. Number the parent chain beginning from

the end closest to the• first branch.

• 3. Identify the alkyl groups and the carbon number on the parent

• chain they are attached to.• 4. List the alkyl groups in alphabetical order and

the number• where the attachment occurs. (Separate

numbers from words• with hyphens).• 5. Finally, list the parent name.

• Ex: • CH3CH2CHClCH2CH=CHCHBrCH3

• 2-bromo-5-chloro-3-octene

Learning Check Alk4

A. CH3 CH3

CH3CHCH2CHCH3

B. CH3 CH3

CH3CH2CHCH2CCH2CH3

CH3

Solution Alk4

A. CH3 CH3

CH3CHCH2CHCH3 2,4-dimethylpentane

B. CH3 CH3

CH3CH2CHCH2CCH2CH3

CH3 3,3,5-trimethylheptane

Learning Check Alk5

Write a condensed structure forA. 3,4-dimethylheptane

B. 2,2-dimethyloctane

Solution Alk5

A. 3,4-dimethylheptane CH3

CH3CH2CHCHCH2CH2CH3

CH3

B. 2,2-dimethyloctane CH3

CH3CCH2CH2CH2CH2CH2CH3

CH3

CycloalkanesCyclopropane CH2

CH2 CH2

Cyclobutane CH2

CH2

CH2 CH2

More Cycloalkanes

Cyclopentane CH2

CH2 CH2

CH2 CH2

Cyclohexane CH2

CH2 CH2

CH2 CH2

CH2

Naming Cycloalkanes with Side Groups

Number of Naming side groups 1. Side group name goes in front of the cycloalkane

name. 2. Number the ring in the direction that gives the lowest

numbers to the side groups.

Cycloalkanes with Side Groups

CH3

CH3

CH3

CH3

CH3

CH3

methylcyclopentane

1,2-dimethylcyclopentane

1,2,4-trimethylcyclohexane

Learning Check Alk8CH3

CH3

CH3

CH3

CH3

Solution Alk8

1,3-dimethylcyclohexane

methylcyclopentane

1,2-dimethylcyclobutane

CH3

CH3

CH3

CH3

CH3

Aromatic Compounds and Benzene

Aromatic compounds contain benzene.

Benzene, C6H6 , is represented as a six carbon ring with 3 double bonds.

Two possible can be drawn to show benzene in this form.

H

H

H

H

H

H

HH

H

H

H

H

Benzene Structure

The structures for benzene can also be written as a single structure where the alternating double bonds are written as a circle within the ring.

Benzenestructure

Aromatic Compounds in Nature and Health

Many aromatic compounds are common in nature and in medicine.

COOH

COOCH3

CHO

OCH3

OH

Aspirin Vanillin

CHCOOH

CH3

CH3CHCH2

CH3

Ibuprofen

Naming Aromatic Compounds

Aromatic compounds are named with benzene as the parent chain. One side group is named in front of the name benzene.

methylbenzene chlorobenzene (toluene)

CH3 Cl

Naming Aromatic Compounds

When two groups are attached to benzene, the ring is numbered to give the lower numbers to the side groups. The prefixes ortho (1,2), meta (1,3-) and para (1,4-) are also used.

CH3

CH3

Cl

Cl

Cl

CH3

1,2-dimethylbenzene 1,3-dichlorobenzene 1-chloro-4-methylbenzene

(ortho-dimethylbenzene) (meta-dichlorobenzene) (para-chloromethylbenzene)

Some Common Names

Some substituted benzene rings also use a common name. Then naming with additional more side groups uses the ortho-, meta-, para- system.

CH3

Cl

CH3 OH

Toluene meta-chlorotoluene phenol(Methylbenzene) (meta-chloromethylbenzene) (hydroxybenzene)

Learning Check Alk9

Select the names for each structure:

1. Chlorocyclohexane2. Chlorobenzene3. 1-chlorobenzene

1. Meta-methyltoluene2. Meta-dimethylbenzene3. 1,3-dimethylbenzene

Cl

CH3

CH3

Solution Alk9

Select the names for each structure:

2. Chlorobenzene

1. Meta-methyltoluene2. Meta-dimethylbenzene3. 1,3-dimethylbenzene

Cl

CH3

CH3

Learning Check Alk10

Write the structural formulas for each of the following:A. 1,3-dichlorobenzene

B. Ortho-chlorotoluene

Solution Alk10

Write the structural formulas for each of the following:A. 1,3-dichlorobenzene

B. Ortho-chlorotoluene

Cl

ClCH3

Cl

Isomers

Types of isomerism

Isomerism

Structural isomerism

Stereoisomerism

Geometric isomerism

Optical isomerism

Isomers- structural

Same molecular formula

Same number and types of atoms

Different arrangement of atoms

isomers

• Isomers- all the possible spatial arrangements for a given hydrocarbon.

• Follow these steps=• 1. start with the longest straight chain.• 2. shorten the chain by one carbon, and add

that extra carbon as a methyl group in all the possible positions starting from the left and moving right.

• 3. check each time to make sure the names don’t repeat.

• 4. shorten the chain by 2 carbons. Add each carbon separately as a methyl to all the possible places. Keep your numbering system correct. Then add the 2 carbons as an ethyl group following the same pattern.

• Ex: Try heptane and octane

Examples of Isomers

The formula C4H10 has two different structures

CH3

CH3CH2CH2CH3 CH3CHCH3

Butane 2-methylpropane

When a CH3 is is used to form a branch, it makes a

new isomer of C4H10.

Decane

Draw 4 isomers of decane

H HC

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

c cc

c cc c ccc c c cc

c cc c cc

c cc

c cc c

c

cc c c

cc cc c

c

c

c

Learning Check Alk6

Write 3 isomers of C5H12 and name each.

Solution Alk6

CH3CH2CH2CH2CH3 pentane

CH3

CH3CHCH2CH3 2-methylbutane

CH3

CH3CCH3 2,2-dimethylpropane

CH3

Learning Check Alk7

Write the structural formulas of 3 isomers that have the formula C5H12. Name each.

Solution Alk7

Write the structural formulas of 3 isomers that have the formula C5H12. Name each.

CH3CH2CH2CH2CH3 pentane

CH3 CH3

CH3CHCH2CH3 CH3CCH3

CH3

2-methylbutane 2,2-dimethylpropane

Cis trans isomers

• This also occurs around the double or triple bonds in straight chains.

• Ex: C4H8 has 4 isomers

Cis and Trans Isomers

Double bond is fixed Cis/trans Isomers are possible

CH3 CH3 CH3

CH = CH CH = CH

cis trans CH3

Look at these models

Cis -2-buteneTrans – 2 - butene

Two isomers are not interchangeable.

• Carbon 2 & 3 joined by double bond.

• No free rotation.• Bonds would have to be

broken and reformed.• +270 kJ mol-1 energy needed

to break this bond.• Insufficient energy available

at room temperature.

cis...

• Different names needed to identify isomers.

• Substituent groups on the same side of double bond.

• Cis -2-butene

Cis-2- butene

...and trans.

• “trans” means other side or cross over e.g. trans Atlantic, transplant, trans…..!

• Substituents on opposite sides of double bond.

Trans-2- butene

Different compounds- different properties.

• 1-butene• Cis-2-butene• Trans-2-butene• 2-methylpropene ( isobutene)• Cis is also called the Z isomer for the German

word zusammen = together• Trans are also called the E isomer for the word

entegen = opposite.

Draw all the isomers

• For – C5H10 and C6H12 and name them include all cis /trans isomers

Organic Chemistry:

Functional Groups

Functional Groups

Part of an organic molecule where chemical reactions take place

Composed of an atom or group of atoms Replace a H in the corresponding alkane Provide a way to classify organic compounds

Functional Groups

ClassClass Functional groupFunctional group

AlcoholAlcohol R – OHR – OH

EtherEther R — O — R’R — O — R’

AldehydeAldehyde O O || || R — C — HR — C — H

KetoneKetone O O || || R — C — R’R — C — R’

Carboxylic acidCarboxylic acid O O || || — — C — OHC — OH

EsterEster O O || || R — C — O — R’R — C — O — R’

AmineAmine R’ R’ | | R — N — R’’R — N — R’’

Some Types of Functional Groups

Haloalkane -F, -Cl, -Br CH3Cl

Alcohol -OH CH3OH

Ether -O- CH3-O-CH3

Aldehyde

KetoneC

O

CH3CH

O

C H

O

CH3CCH3

O

More Functional Groups

Carboxylic acid -COOH CH3COOH

Ester -COO- CH3COOCH3

Amine -NH2 CH3NH2

Amide -CONH2 CH3CONH2

Haloalkanes

An alkane in which one or more H atoms is replaced with a halogen (F, Cl, Br, or I)

CH3Br 1-bromomethane

Br (methyl bromide)

CH3CH2CHCH3 2-bromobutane

Cl

chlorocyclobutane

Organic Compounds Containing Halogens

Hydrocarbons: Basic ConceptsHydrocarbons: Basic ConceptsHydrocarbons: Basic ConceptsHydrocarbons: Basic ConceptsTopic 27Topic 27

• Any organic compound that contains a halogen substituent is called a halocarbon.

• If you replace any of the hydrogen atoms in an alkane with a halogen atom, you form an alkyl halide.


• An alkyl halide is an organic compound containing a halogen atom covalently bonded to an aliphatic carbon atom.

• The first four halogens— fluorine, chlorine, bromine, and iodine—are found in many organic compounds.



• For example, chloromethane is the alkyl halide formed when a chlorine atom replaces one of methane’s four hydrogen atoms.



• An aryl halide is an organic compound containing a halogen atom bonded to a benzene ring or other aromatic group.

• The structural formula for an aryl halide is created by first drawing the aromatic structure and then replacing its hydrogen atoms with the halogen atoms specified.


Learning Check HA1

Name the following:

Br

Cl

Cl

Solution HA1

Name the following:

bromocyclopentane

1,3-dichlorocyclohexane

Br

Cl

Cl

Substituents

List other attached atoms or group in alphabetical orderBr = bromo, Cl = chloro

Cl Br

CH3CHCH2CHCH2CH2CH3

4-bromo-2-chloroheptane

Learning Check HA2

The name of this compound is:

Cl CH3

CH3CH2CHCH2CHCH3

1) 2,4-dimethylhexane

2) 3-chloro-5-methylhexane


Solution HA2

The name of this compound is:

Cl CH3

CH3CH2CHCH2CHCH3


Haloalkanes as Anesthetics

Halothane (Fluothane) F Cl

F C C Br

F HFluothane is a haloalkane that is widely used as an anesthetic, which is a compound that decreases the ability of the nerve cells to conduct pain.

Ozone Layer

Ozone layer

Stratosphere(10-30 milesAbove Earth)

Chlorofuorocarbons (CFCs and the Ozone Layer

ozone O3 layer absorbs most of the sun’s harmful radiation.

CFCs - chlorofluorocarbons - are depleting that ozone layer.

CFCs are used as Freons in refrigeration,

air conditioning, and foam insulation. Their use in spray cans is no longer allowed.

Alcohols

• Alcohols have a OH group attached to a C somewhere along the chain.

• The ending changes to “ol”• If there are 2 OH groups the are referred to as

a “diol”• The OH group has to be identified using the

IUPAC numbering system• Ex: CH2ClCHOHCHClCH3

• 1,3-dichloro-2-butanol

Alcohols


• An oxygen-hydrogen group covalently bonded to a carbon atom is called a hydroxyl group (—OH).

group replaces a hydrogen atom of a hydrocarbon is called an alcohol.

• An organic compound in which a hydroxyl

• The general formula for an alcohol is ROH.

Naming Alcohols

A carbon compound that contain -OH (hydroxyl) group

In IUPAC name, the -e in alkane name is replaced with -ol.

CH4 methane

CH3OH methanol (methyl alcohol)

CH3CH3 ethane

CH3CH2OH ethanol (ethyl alcohol)

Ethanol CH3CH2OH

Acts as a depressantKills or disables more people than any other

drug12-15 mg/dL ethanol metabolized by a social

drinkers in one hour 30 mg/dL ethanol metabolized by an alcoholic in

one hour.

Alcohol in Some Products

% Ethanol Product

50% Whiskey, rum, brandy40% Flavoring extracts15-25% Listerine, Nyquil, Scope12% Wine, Dristan, Cepacol3-9% Beer, Lavoris

More Names of Alcohols

IUPAC names for longer chains number the chain from the end nearest the -OH group.

CH3CH2CH2OH 1-propanol

OH CH3CHCH3 2-propanol

CH3 OH CH3CHCH2CH2CHCH3 5-methyl-2-hexanol

Some Typical Alcohols

OH “rubbing alcohol” CH3CHCH3

2-propanol (isopropyl alcohol)

antifreeze HO-CH2-CH2-OH

1,2-ethanediol (ethylene glycol)

OH

glycerolHO-CH2-CH-CH2OH

Ant

i-fre

eze

Learning Check Al 2

Name the following alcohols:A. OH

CH3CHCHCH2CH3

CH3

OH

B.

Solution Al 2

Name the following alcohols:A. OH 3-methyl-2-pentanol

CH3CHCHCH2CH3

CH3

OHB. cyclobutanol

Reactions of Alcohols

CombustionCH3OH + 2O2 CO2 + 2H2O + Heat

Dehydration H OH

H+, heat H-C-C-H H-C=C-H + H2O

H H H H alcohol alkene

Aldehydes and Ketones

In an aldehyde, an H atom is attached to a carbonyl group

O carbonyl group CH3-C-HIn a ketone, two carbon groups are attached to a

carbonyl group

O carbonyl group CH3-C-CH3

aldehydes

• Aldehydes contain a CHO attached to the end of a carbon chain The C has a double bonded O and a single bonded H attached to it. Since it is at the end of a chain there is no need to number.

• The ending changes to “al”• Ex: CH3CHICH2CH2CHICHO

• 2,5-diiodohexanal

Naming Aldehydes

IUPAC Replace the -e in the alkane name -alCommon Add aldehyde to the prefixes form (1C),

acet (2C), propion(3), and butry(4C) O O O

IIH-C-H CH3-C-H CH3CH2C-H

methanal ethanal propanal (formaldehyde) (acetaldehyde) (propionaldehyde)

Aldehydes as Flavorings

Benzaldehyde Vanillin Cinnamaldehyde(almonds) (vanilla beans) (cinnamon)

CH=CH CH

OCH

O

HO

OCH3

CH

O

Glucose is an aldehyde

glucose

C

OH

C

CHO H

CH OH

C

CH2OH

OH

OHH

H

Ketones

• Ketones have a C=O bond embedded within a chain .

• The IUPAC system of numbering applies here and the “e” of the chain gets replaced with a “one” ending

• O• ║• Ex: CH3CH2CCH2CH2CH2CH2CH3 • 3-octanone

Naming Ketones

In the IUPAC name, the -e in the alkane name is replaced with -one

In the common name, add the word ketone after naming the alkyl groups attached to the

carbonyl group O O

II

CH3 -C-CH3 CH3-C-CH2-CH3

2- Propanone 2-Butanone (Dimethyl ketone) (Ethyl methyl ketone)

Cyclohexanone

O

Ketones

O O

Butter flavor CH3-C-C-CH3 butanedione

O Clove flavor CH3-C-CH2CH2CH2CH2CH3

2-heptanone

Fructose is a Ketone

D-Fructose

H2OHC

C

CHO H

C

O

H OH

C

CH2OH

OHH

Ketones as Hormones

Cortisone

O

CH2OH

OCH3

CH3

O OH

Learning Check AK 1

Classify each as an aldehyde (1), ketone (2) or neither(3).

O II

A. CH3CH2CCH3 B. CH3-O-CH3

CH3 O

C. CH3-C-CH2CH D. CH3

O

Solution AK 1

Classify each as an aldehyde (1), ketone (2) or neither(3).

OII

A. CH3CH2CCH3 2 B. CH3-O-CH3 3

CH3 O

C. CH3-C-CH2CH 1 D. 2 CH3

O

Learning Check AK 2

Name the following O

A. CH3CH2CCH3 B.

CH3 O II

C. CH3-C-CH2CH CH3

O

Solution AK 2

O

A. CH3CH2CCH3 B.

2-butanone (ethyl methyl ketone)

CH3 O

C. CH3-C-CH2CH cyclohexanone CH3

2,2-dimethylbutanal

O

Learning Check AK 3

Draw the structural formulas for each:

A. 3-Methylpentanal

B. 2,3-Dichloropropanal

C. 3-Methyl-2-butanone

Solution AK 3

Draw the structural formulas for each: CH3 O

A. 4-Methylpentanal CH3CHCHCH2CH Br O

B. 2,3-Dibromopropanal Br-CH2CHCH

O

C. 3-Methyl-2-butanone CH3CHCCH3

CH3

ethers

• Have an O atom within the carbon chain itself. In other words C-O-C.

• Components of the chain on both sides of the O have to be named.

• Ethers have the general formula ROR′.

• No numbering system is needed since the chain is broken.

• The name remains the same just add the ending ether

Ethers

• The simplest ether is one in which oxygen is bonded to two methyl groups.

• Note the relationship between methanol and methyl ether in the following diagram.

Ethers

• Contain an -O- between two carbon groups• Simple ethers named from -yl names of the

attached groups and adding ether.

CH3-O-CH3 dimethyl ether

CH3-O-CH2CH3 ethyl methyl ether

• Ex: CH3OCH2CH2CH2CH2CH3

• Methyl-n-pentyl ether The “n” signifies that the carbons are in a straight chain with no branches.

Ethers as Anesthetics

Anesthetics inhibit pain signals to the brainCH3CH2-O-CH2CH3 used for over a century (Morton, 1846)Causes nausea and is highly flammable1960s developed nonflammable anesthetics

Cl F F Cl F H

H-C-C-O-C-H H-C-C-O-C-H

F F F H F H Ethane(enflurane) Penthrane

MTBE

Methyl tert-butyl ether

CH3

CH3-O-C-CH3

CH3

Second in production or organic chemicals Additive to improve gasoline performance

Carboxylic acids

• These compounds end with a COOH group where the C has a double bonded O and a single bonded OH

• The ending of the parent chain changes from “ane” etc. to “oic” and add the word acid

• Ex: CH3CH2CH2COOH

• Butanoic acid

Carboxyl Group

Carboxylic acids contain the carboxyl group on carbon 1.

O

CH3 — C—OH = CH3—COOH

carboxyl group

Naming Carboxylic Acids

Formula IUPAC Common alkan -oic acid prefix – ic acid

HCOOH methanoic acid formic acid

CH3COOH ethanoic acid acetic acid

CH3CH2COOH propanoic acid propionic acid

CH3CH2CH2COOH butanoic acid butyric acid

Naming Rules

• Identify longest chain• (IUPAC) Number carboxyl carbon as 1• • CH3

|CH3 — CH—CH2 —COOHIUPAC 3-methylbutanoic acid

Learning Check CA1

Give IUPAC and common names:

A. CH3COOH

CH3

|

B. CH3CHCOOH

Solution CA 1

A. CH3COOH

ethanoic acid; acetic acid

CH3

|

B. CH3CHCOOH

2-methylpropanoic acid;

Properties

• Carboxylic acids are weak acids

CH3COOH + H2O CH3COO– + H3O+

• Neutralized by a baseCH3COOH + NaOH CH3COO– Na+ + H2O

Phenols

IUPAC name for benzene with a hydroxyl groupMany are used as antiseptics and disinfectants

OH

Phenol

Phenols in Medicine

OH

OH

OH OH

OH

CH2CH2CH2CH2CH2CH3

Resorcinol 4-Hexylresorcinal(antiseptic) (antiseptic)

Phenol

Compounds with Oxygen Atoms

Alcohols-OH hydroxyl CH3-OH

CH3CH2-OH

Phenols

Ethers -O- CH3-O-CH3

OHOH

Learning Check Al1

Classify each as an alcohol (1), phenol (2), or an ether (3):

A. _____ CH3CH2-O-CH3 C. _____ CH3CH2OH

B. _____

OH

CH3

Solution Al 1

Classify each as an alcohol (1), phenol (2), or an ether (3):

A. __3__ CH3CH2-O-CH3 C. __1__ CH3CH2OH

B. _ 2__

OH

CH3

Thiols

Contain the functional group -SH Named by adding thiol to the name of the longest

carbon chainNumber the -SH group in longer chains

CH3-SH methanethiol

CH3-CH2SH ethanethiol

SH

CH3-CH-CH3 2-propanethiol

ThiolsMany thiols have disagreeable odorsUsed to detect gas leakFound in onions, oysters, garlic and oysters

Onions CH3CH2CH2-SH 1-propanethiolGarlic CH2= CHCH2-SH 2-propene-1-thiolSkunk spray

CH3 trans-2-butene-1-thiol

CH = CH

CH2SH

Amines

• Organic compounds of nitrogen N• Classified as primary, secondary, tertiary

CH3 CH3

CH3—NH2 CH3—NH CH3—N — CH3

1° 2° 3°

Naming Amines

IUPAC aminoalkane Common alkylamine

CH3CH2NH2 CH3—NH —CH3

aminoethane N-methylaminomethane(ethylamine) (dimethylamine)

NH2

|

CH3CHCH3

2-aminopropane Aniline N-methylaniline(isopropylamine)

NH2 NH CH3

Learning Check AM1

Give the common name and classify:

A. CH3NHCH2CH3

CH3

|B. CH3CH2NCH3

Solution AM1

A. CH3NHCH2CH3

ethylmethylamine, 2°

CH3

|B. CH3CH2NCH3

ethyldimethylamine, 3°

Alkaloids

• Physiologically active nitrogen-containing compounds

• Obtained from plants• Used as anesthetics, antidepressants, and

stimulants• Many are addictive

Nicotine

N

CH3

Nicotine, leaves of tobacco plant

Caffeine

N

N N

NCH3

O

O CH3

CH3

Caffeine, coffee beans and tea

Procaine

NH2N

CH3CH2

CH3CH2

CH2CH2 O C

O

Procaine (novocaine), painkiller

Leaning Check AM2

Write a structural formula for

A. 1-aminopentane

B. 1,3-diaminocyclohexane

Solution AM2

A. 1-aminopentane CH3CH2CH2CH2CH2-NH2

B. 1,3-diaminocyclohexane

NH2

NH2

Amides

Derivatives of carboxylic acids where an amino (-NH2) group replaces the –OH group

. O O

CH3 — C—OH CH3 — C—NH2

carboxylic acid amide ethanoic acid ethanamide

Naming Amides

Alkanamide from acid name

O methanamide (IUPAC)HC–NH2 formamide (common)

O propanamide (IUPAC)CH3CH2C–NH2 propionamide(common)

Naming Amides with N-Groups

O CH3C–NHCH3 N-methylethanamide (IUPAC)

N-methylacetamide (common) O

CH3CH2C–N(CH3)2

N,N-dimethylpropanamideN,N-dimethylpropionamide

Aromatic Amides

C

O

NH2

Benzamide

C

O

NHCH3

N methylbenzamide -

Learning Check AM3

Name the following amides: O

A. CH3CH2CH2C–NH2

O

B. CH3C–N(CH2CH3)2

Solution AM3

O

A. CH3CH2CH2C–NH2

butanamide; butryamide (common)

O

B. CH3C–N(CH2CH3)2

N,N-diethylethanamide;

N,N-diethylacetamide

Learning Check AM4

Draw the structures of A. PentanamideB. N-methylbutyramide

Solution AM4

A. Pentanamide O

CH3CH2CH2CH2C–NH2

B. N-methylbutyramide O

CH3CH2CH2C–NHCH3

Esters

In and ester, the H in the carboxyl group is replaced with an alkyl group

O

CH3 — C—O —CH3 = CH3—COO —CH3

ester group

Esters in Plants

Esters give flowers and fruits their pleasant fragances and flavors.

Naming Esters

• Name the alkyl from the alcohol –O-• Name the acid with the C=O with –ate acid alcohol

O methyl

CH3 — C—O —CH3

Ethanoate methyl ethanoate (IUPAC)(acetate) methyl acetate (common)

Some Esters and Their Names

Flavor/OdorRaspberries

HCOOCH2CH3 ethyl methanoate (IUPAC)

ethyl formate (common)

Pineapples

CH3CH2CH2 COOCH2CH3

ethyl butanoate (IUPAC)

ethyl butyrate (common)

Learning Check CA 2

Give the IUPAC and common names of the following compound, which is responsible for the flavor and odor of pears.

O

CH3 — C—O —CH2CH2CH3

Solution CA2

O propyl

CH3 — C—O —CH2CH2CH3

proply ethananoate (IUPAC)propyl acetate (common)

Learning Check CA 3

Draw the structure of the following compounds:

A. 3-bromobutanoic acid

B. Ethyl propionoate

conformations

• 3 dimensional molecular structures interrelated by rotations about the bonds.

• Ex. Ethane C2H6

• Can be described as eclipsed and staggered.

• See handout

Hydrogenation

Adds a hydrogen atom to each carbon atom of a double bond

H H H H

Ni

H–C=C–H + H2 H–C–C–H

H H

ethene ethane

Products of Hydrogenation

Adding H2 to vegetable oils produces compounds with higher melting points

Margarines

Soft margarines

Shortenings (solid)

Learning Check HA4

What is the product of adding H2 (Ni catalyst) to 1-butene?

Solution HA4

What is the product of adding H2 (Ni catalyst) to 1-butene?

Ni

CH2=CHCH2CH3 + H2

CH3CH2CH2CH3

Adding Halogens

Halogens also add to the double bond of an alkene.

H2CCH2 + Cl2

H2C CH2

Cl Cl

CH3C CCH2CH3 + Br2 CH3C CCH2CH3

Br Br

Br Br

Learning Check HA5

Write the product of the following addition reactions:

CH3CH=CHCH3 + H2

+ Br2

Solution HA5

Write the product of the following addition reactions:

CH3CH=CHCH3 + H2 CH3CH2CH2CH3

+ Br2Br

Br

Unsaturated Fatty Acids

Fatty acids in vegetable oils are omega-6 acids (the first double bond occurs at carbon 6 counting from the methyl group)

A common omega-6 acid is linoleic acid

CH3CH2CH2CH2CH2CH=CHCH2CH=CH(CH2)7COOH

6linoleic acid, a fatty acid

Trans Fats

In vegetable oils, the unsaturated fats usually contain cis double bonds.

During hydrogenation, some cis double bonds are converted to trans double bonds (more stable) causing a change in the fatty acid structure

If a label states “partially” or “fully hydrogenated”, the fats contain trans fatty acids.

Trans Fats

In the US, it is estimated that 2-4% of our total Calories is in the form of trans fatty acid.

trans fatty acids behave like saturated fatty acids in the body.

Several studies reported that trans fatty acids raise LDL-cholesterol. Some studies also report that trans fatty acid lower HDL-cholesterol

The trans fatty acids controversy will continue to be debated.

Fats and AtheroschlerosisInuit people of Alaska have a high fat diet and high

blood cholesterol levels, but a very low occurrence of atherosclerosis and heart attacks.

Fat in the Intuit diet was primarily from fish such as salmon, tuna and herring rather than from land animals (as in the American diet).

Omega-3 Fatty Acids

Fatty acids in the fish oils are mostly the omega-3 type (first double bond occurs at the third carbon counting from the methyl group).

linolenic acid 18 carbon atoms

CH3CH2CH=CHCH2CH=CHCH2CH=CH(CH2)7COOH

eicosapentaenoic acid (EPA) 20 carbon atoms

CH3CH2(CH=CHCH2)5(CH2)2COOH

Learning Check HA6

(1) Ture or (2) False

A. ____ There are more unsaturated fats in vegetable oils.

B. ____ Vegetable oils have more omega-3 oils than found in fish.

C. ____ Hydrogenation of oils converts some cis-double bonds to trans- double bonds.

D. ____ Animal fats have more saturated fats.

Documents

Organic Nomenclature Organic Compounds Organic Compounds - any covalently bonded compound containing carbon (except carbonates and oxides)