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Organic ChemistryOrganic Chemistry
a branch of chemistry concerned a branch of chemistry concerned with the study of carbon and its with the study of carbon and its compounds.compounds.
HydrocarbonsHydrocarbons
the simplest class of organic the simplest class of organic compounds containing carbon & compounds containing carbon & hydrogen onlyhydrogen only
hydrocarbons
aromaticaliphatic
alkanes cycloalkanes alkenes alkynes
Aliphatic Aliphatic HydrocarbonsHydrocarbons
A hydrocarbon with no aromatic ring
Example:CH31
CH2
CH3
CH34
CH3
CH3
Aromatic Aromatic HydrocarbonsHydrocarbons
a hydrocarbon containing one or more rings with delocalized electron systems
(example is benzene, C6H6) CH
CH
CH
CH
CH
CH
AlkanesAlkanes
are saturated hydrocarbons general formula is Cgeneral formula is CnnHH2n+2 2n+2
ex: CHex: CH4 4 (methane)(methane) single covalent bonds (C-C) between single covalent bonds (C-C) between
carbon to carbon molecules are carbon to carbon molecules are presentpresent
uses the –ane ending in its nameuses the –ane ending in its name
AlkanesAlkanes
The first 10 alkanes are named as follows:
CHCH44 methanemethaneCC66HH1414 hexanehexane
CC22HH66ethaneethane CC77HH1616 heptaneheptane
CC33HH88propanepropane CC88HH1818 octaneoctane
CC44HH1010 butanebutane CC99HH2020 nonanenonane
CC55HH1212 pentanepentane CC1010HH2222 decanedecane
CycloalkanesCycloalkanes
alkanes whose carbon atoms are alkanes whose carbon atoms are joined in ringsjoined in rings
general formula is Cgeneral formula is CnnHH2n2n
ex: C6H12 (cyclohexane)
uses the prefix cyclo and –ane ending in its name
CH2
CH2
CH2
CH2
CH2
CH2
Alkenes (Olefins)Alkenes (Olefins)
unsaturated hydrocarbons that unsaturated hydrocarbons that contain C=Ccontain C=C
general formula is Cgeneral formula is CnnHH2n2n (same as (same as
cyloalkane)cyloalkane) ex:Cex:C22HH44 (ethene) (ethene) uses the –ene ending in its nameuses the –ene ending in its name
CH2 CH2
Alkynes (Paraffins)Alkynes (Paraffins)
unsaturated hydrocarbons that unsaturated hydrocarbons that contain Ccontain CCC
general formula is Cgeneral formula is CnnHH2n-22n-2
ex: C2H2 (ethyne)
uses the –yne ending in its nameuses the –yne ending in its name
CH CH
Important NotesImportant Notes
an alkane less one hydrogen atom an alkane less one hydrogen atom is called an is called an alkyl groupalkyl group (example (example is when a hydrogen atom is is when a hydrogen atom is removed from methane, it is called removed from methane, it is called methylmethyl, -CH, -CH33))
Naming AlkanesNaming Alkanes
Step 1:Step 1: Determine the parent name by Determine the parent name by
finding the longest continuous chain finding the longest continuous chain of carbon atoms in the molecule. The of carbon atoms in the molecule. The parent name is the name of the parent name is the name of the alkane corresponding to the longest alkane corresponding to the longest continuous carbon chain. The longest continuous carbon chain. The longest chain may not be always written chain may not be always written horizontally.horizontally.
Naming AlkanesNaming Alkanes
CH31
CH22
CH23
CH24
CH25
CH36
hexane
CH36
CH25 CH2
4
CH3 CH3
CH22
CH31
3 – methylhexane3 – methylhexane
Naming AlkanesNaming Alkanes
If the molecule contains two chains If the molecule contains two chains of equal length, choose the one of equal length, choose the one with the greater number of with the greater number of substituents as the parent chain.substituents as the parent chain.
CH31
CH2
CH3
CH3
CH2 CH3
CH24
CH25
CH26
CH37
Naming AlkanesNaming Alkanes
Step 2Step 2 name each substituent and precede name each substituent and precede
this name with the number of this name with the number of carbon atom on the parent chain to carbon atom on the parent chain to which it is bonded.which it is bonded.
Naming AlkanesNaming Alkanes
Parent: butane Substituent: methyl Location: C2- methyl Name: 2 – methylbutane
CH31
CH2
CH23
CH34
CH3
Naming AlkanesNaming Alkanes
Two or more identical substituents present in a molecule are indicated by the use of the prefixes di for 2, tri for 3 tetra for 4, etc. Each of the identical substituents must have a number
Naming AlkanesNaming Alkanes
Parent: butane Substituent: methyl Location: C2 and C3- methyl Name: 2,3 –dimethylbutane
CH31
CH2
CH3
CH34
CH3
CH3
Naming AlkanesNaming Alkanes
When two or more substituents are present, their names are listed in alphabetical order
Naming AlkanesNaming Alkanes
Parent: heptane Substituent: methyl and ethyl Location: C2- methyl and C3- ethyl Name: 3 – ethyl – 2 – methylheptane Note: the name of the compound is
written in single word.
CH31
CH2
CH3
CH3
CH2 CH3
CH24
CH25
CH26
CH37
Naming Alkenes & Naming Alkenes & AlkynesAlkynes
Step 1: Choose the longest continuous carbon
chain that contains the double/triple bond as the parent chain.
Step 2: Number the chain to give the lowest
number to the first carbon of the double/triple bond.
Naming Alkenes & Naming Alkenes & AlkynesAlkynes
Step 3: Substitute the ending -ene for ending –ane
in the name of the corresponding alkane to obtain the parent alkene name and substitute –yne to obtain the parent alkyne. The position of the double/triple bond is indicated by a number.
Step 4: Write the complete name of the compound
with the correct number of all substituents, which are listed in alphabetical order.
ExamplesExamples
Parent: octene Location: C3 Substituent: methyl, ethyl & bromo Location: C3,C6- methyl; C4 bromo; C6-ethyl Name:4-Bromo–6-ethyl-3,6-dimethyl-3-
octene
CH22
C3
C4
Br
CH31
CH25
C6
CH2
CH27
CH38
CH3
CH3CH3
ExamplesExamples
Parent: butyne Location: C1 Substituent: methyl Location: C3 Name: 3 – methyl – 1- butyne
or 3- methylbutyne
CH3
C2
CH1
CH3
CH34
Aromatics: BenzeneAromatics: Benzene
Monosubstituted benzenes are named by combining the substituent name w/ the word benzene.
Name: 1 - ethylbenzene
C1
CH2
CH6
CH3
CH5
CH4
CH2 CH3
For disubstituted benzenes the 3 possible isomers are named using the prefixes ortho (o), meta (m) & para (p) to designate the 1,2 – 1,3 & 1,4 –relationships of sustituents on the benzene ring:
Name: 1,3-Dibromobenzene or meta-Dibromobenzene
CH2
C3
C1
CH4
CH6
CH5
Br
Br
Exercises:Exercises:
Draw the structure of the following hydrocarbons:
1. 2,2-dimethylpentane2. 4-ethyl-2,3-dimethyloctane3. 3-ethyl-3-methyl-1-pentene4. 1,3- dibromobenzene
Exercises:Exercises:
Give the name of the following Hydrocarbons:
1.
2.
CH3
C C CH
CH3
CH2 CH3
CH3 CH
CH3
C
CH2
CH3
CH
CH2 CH
CH3
CH2 CH3
3. 4.
5. 6.
CH
CH
CH
C
C
CH
CH3
CH3
Cl
Br
Br
CH2 C
CH3
CH C CH CH3
CH CH3
CH3
Cl CH2
CH2
CH
CH2
CH3
Hydrocarbon Hydrocarbon DerivativesDerivatives
these are compounds that are formed when one, two or three hydrogen atoms in the hydrocarbon molecules are replaced by atoms or group of atoms that are responsible for the properties of that compound. This group of atoms is called the functional group.
ALCOHOLS
Contains the –OH group (hydroxyl)ex:
CH3-OH methanol
CH3CH2-OH ethanol
phenol
OH
Some Typical Alcohols OH “rubbing alcohol” CH3CHCH3
2-propanol (isopropyl alcohol)
antifreeze HO-CH2-CH2-OH
1,2-ethanediol (ethylene glycol)
OH
glycerol HO-CH2-CH-CH2OH
Ant
i-fre
eze
Ethers
Contain an -O- between two carbon groups
CH3-O-CH3 dimethyl ether
CH3-O-CH2CH3 ethyl methyl
ether
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 as Flavorings
Benzaldehyde Vanillin Cinnamaldehyde(almonds) (vanilla beans) (cinnamon)
CH=CH CH
OCH
O
HO
OCH3
CH
O
Ketones
O O
Butter flavor CH3-C-C-CH3
butanedione
propanone
CH3
C
CH3
O
acetone
Amines
Organic compounds of nitrogen N Classified as primary, secondary, tertiary
CH3 CH3
CH3—NH2 CH3—NH CH3—N — CH3
1° 2° 3°
Alkaloids
Physiologically active nitrogen-containing compounds
Obtained from plants Used as anesthetics, antidepressants, and
stimulants Many are addictive
Some Common Amines
N
CH3
Nicotine, leaves of tobacco plant
N
N N
NCH3
O
O CH3
CH3
Caffeine, coffee beans and tea
Some Common Amines
NH2N
CH3CH2
CH3CH2
CH2CH2 O C
O
Procaine (novocaine), painkiller
Carboxylic Acid
Carboxylic acids contain the carboxyl group on carbon 1.
O
CH3 — C—OH CH3—COOH
carboxyl group
Some Carboxylic Acids & their Names
OH C CH2 C CH2
O
OH
C C OH
OO
OH
2-hydroxypropane-1,2,3-tricarboxylic acid
Citric acid COH
O
OC
CH3
O
2-(acetyloxy)benzoic acid
Aspirin
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
acetic acid acetamide
Some Amides & their Names
O
CH3C–NHCH3 N-methylethanamide
(IUPAC)N-methylacetamide
(common)C
O
NH2
Benzamide
C
O
NHCH3
N methylbenzamide -
Esters
In an 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 fragrances and flavors.
Some Esters and Their Names
Flavor/OdorRaspberries
HCOOCH2CH3 ethyl methanoate (IUPAC)
ethyl formate (common)
Pineapples
CH3CH2CH2 COOCH2CH3
ethyl butanoate (IUPAC)
ethyl butyrate (common)
Exercises:
Identify the functional groups present in the following compounds:
O
OH
CH3 CH2
CH2 NH
CH3
CH2
CH
OH
CH3
CH3
H C
CH
O
CH3
CH3
(1)
(2)
(4)
(3)
CH3 C
O
NH
CH3
CH3 C
O
CH
CH3
CH3
CH3 CH
CH3
O CH3
CH3 C
O
O
(5)
(8)
(7)
(6)