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CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
TOPIC: ORGANIC CHEMISTRY
Organic Chemistry is the study of carbon and the other common nonmetals it is connected to:
____ , ____ , ____ & ____ .
Some organic molecules are made of just carbons and hydrogens and are aptly named _____________________.
C
H
H
H
C
H
H
C
H
H
H
A B
CC
CC
O
H
H
H H H
H
H
H
C
H
H
H
N H
H
C D
H – Cl
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: STRUCTURAL FORMULAS
Your typical organic molecule can be drawn in a few different ways.
For example if you take a look at pentane, C5H12.
C
H
H
H
C C C C
H
H
H
H
H
H
H
H
H
Structural Formula Condensed Formula
CH3–CH2–CH2–CH2–CH3
Skeletal Formula
EXAMPLE 1: Determine the molecular formula for the following organic compound.
EXAMPLE 2: Convert the following structural formula into its condensed formula.
C
H
H
H
C C C C
H
H
CH3
H
H
H
C
H
H
H
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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PRACTICE: STRUCTURAL FORMULAS 1
EXAMPLE 1: Determine the molecular formula for the following organic compound.
EXAMPLE 2: Determine the molecular formula for the following organic compound.
HN
NH
O
O
Uracil (U) RNA
EXAMPLE 3: Convert the following structural formula into the carbon skeleton formula, otherwise known as a kekulé
structure.
C
O
HO C O C C
H
H
C
H
N
H H
H
H
H
H
H
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: CHIRALITY
A molecule is chiral when it possesses a carbon that has ________ unique groups attached to it.
This molecule is said to be non-superimposable.
The mirror image of any chiral molecule is called an _____________________ and together they
are referred to as ____________ isomers or _____________ isomers.
Br
C
HOCH3
H
mirror
Br
C
OHH3C
H
EXAMPLE 1: Identify the compound that possesses an asymmetric center.
Cl C
H
H
H
A B C D
C C
CH3
C
CH3
HO–CH2 H C C
F
H
H
H
Cl
H
H3C
Cl
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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PRACTICE: CHIRALITY 1
EXAMPLE 1: From the previous question draw the mirror image of the chiral molecule.
EXAMPLE 2: Draw the mirror images for the following molecule.
Mirror Method Inversion Method
OHCl
PRACTICE: Draw the mirror images for the following molecule.
Mirror Method Inversion Method
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: OPTICAL ACTIVITY
We recently learned that a chiral molecule is one that possesses a carbon connected to four distinct groups.
One key feature of chiral molecules is that they rotate plane polarized light.
Clockwise rotation = dextrorotatory (d) or (+) Counterclockwise rotation = levorotatory (l) or (–)
Chiral Solution
Chiral Solution
The names and degrees of rotation have nothing to do with the chirality of the compounds.
EXAMPLE: Which of the following compounds would be optically active?
A B C D
Cl
Br
OHF
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: HYDROCARBONS
The term of “hydrocarbon” refers to compounds that contain only carbons and hydrogens. These compounds may
possess single, double or triple bonds.
Carbons are ___________________ meaning that when they are neutral they must make 4 bonds.
C
H
H
H
C
H
H
H
Alkane
C
H
H
C
H
H
Alkene
CH C H
Alkyne
C
CC
C
CC
H
H
H
H
H
H
Benzene
Alkane Prefixes The name of alkanes is based on the number of carbons in the compound. These alkane “prefixes” must be
memorized in order to name more complex structures later on in the chapter.
# of Carbons
Alkane Prefix # of
Carbons
Alkane Prefix
1
6
2
7
3
8
4
9
5
10
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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Alkanes Alkanes are hydrocarbons that contain only single bonds. They are sometimes referred to simply as “ saturated”
hydrocarbons.
Since all of the carbons are connected to 4 electron groups they all have an _______ hybridization.
Alkanes have a generic formula of _____________.
C
H
H
H
C
H
H
C
Propane
C
H
H
H
C
H
H
H
Ethane
H
H
H
EXAMPLE 1: Determine the formula and name of a hydrocarbon that contains only single bonds and 8 carbons. There is a direct relationship between an alkane’s weight and it’s measured boiling point.
Generally, the _____________ the molecular weight of an alkane the higher its boiling point.
Number of Carbons Physical State Usage
Up to 4
Gas
Cooking and Heating
5 to 7
Volatile Liquids
Gasoline and solvents
6 to 18
Liquids
Gasoline
12 to 24
Liquids
Jet Fuel
16 to 50
High Boiling Liquids
Diesel, heating oils and grease
Over 50
Solids
Petroleum jelly, waxes
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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Alkenes Alkenes are hydrocarbons that contain at least one double bond. They are sometimes referred to simply as
“unsaturated” hydrocarbons.
The double bonded carbons are connected to 3 electron groups and so have an _______ hybridization.
Alkenes and cycloalkanes have a generic formula of _____________.
CH
H
C
H
C
Propene
C
H
H
C
H
H
Ethene
H
H
H
Cyclohexane
EXAMPLE 2: Determine the formula and simplest name of a hydrocarbon that contains one double bond and 6 carbons.
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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Alkynes Alkynes are hydrocarbons that contain at least one triple bond. They are sometimes referred to simply as
“unsaturated” hydrocarbons just like the alkenes.
The triple bonded carbons are connected to 2 electron groups and so have an _______ hybridization.
Alkynes have a generic formula of _____________.
CH C C
Propyne
CH C H
Ethyne
H
H
H
EXAMPLE 3: Determine the formula and simplest name of a hydrocarbon that contains one triple bond and 9 carbons.
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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Aromatics Aromatic compounds have a benzene ring (C6H6) as their major defining feature.
C
CC
C
CC H
H
H
H
H
H
C
CC
C
CC H
H
H
H
H
H
Resonance Structures
C
CC
C
CC H
H
H
H
H
H
Resonance Hybrid
Benzene rings can be found in many everyday compounds from fossil fuels to even some vital medications.
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: ALKYL GROUPS
The removal of a hydrogen atom from an alkane compound creates an alkyl group. Remembering these alkyl groups
are the first step in learning how to name organic compounds.
H C
H
H
H
Methane
C
H
H
H
Methyl
When you have a two carbon chain then the alkyl name will be ______________.
CH3 – CH3
________________
CH2CH3
________________
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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When you have a three carbon chain then the alkyl name will be __________________ or __________________.
________________
CH3–CH2–CH3
________________
CH2CH2CH3 CH3CHCH3
________________
When you have four carbons then the alkyl names will be ____________________ , ____________________ ,
_____________________ or _____________________ .
________________
CH3–CH2–CH2–CH3
________________
CH2CH2CH2CH3 CH3CHCH2CH3
________________
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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________________
CH3–CH–CH3
________________ ________________
CH3
CH2–CH–CH3
CH3 CH3–C
CH3
CH3
EXAMPLE: Based on your knowledge of chemical structures draw the three isomers of C5H12 (pentane).
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: NAMING ALKANES When naming any alkane compound there is a set of rules you should follow to get the correct answer.
1. Find the longest carbon chain and assign a root name accordingly.
If there is a tie between longest chains, choose the chain that gives _____________ substituents.
Substituents are the groups that branch off the main chain and weren’t counted as part of the main chain.
2. Number the chain from the end closest to a substituent.
3. Substituents will be named alphabetically and a number will accompany the location of their attachment.
4. If more than one of a similar alkyl group is present then we must use numerical prefixes to describe the
number of them.
__________ – 2 __________ – 3 __________ – 4 __________ – 5
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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PRACTICE: NAMING ALKANES 1
EXAMPLE 1: Naming the following alkane compound.
a) EXAMPLE 2: Naming the following alkane compound.
b) EXAMPLE 3: Naming the following alkane compound.
c )
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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PRACTICE: NAMING ALKANES 2
EXAMPLE 4: Determine the structure for the following alkane compound.
3, 4, 5-trimethyldecane
EXAMPLE 5: Determine the structure for the following alkane compound.
4-tert-butyloctane
EXAMPLE 6: Determine the structure for the following alkane compound.
1-bromo-2,3-dichlorocycloheptane
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: NAMING ALKENES Naming an alkene is similar to naming an alkane with a few differences.
1. Find the longest carbon chain and change the “ane” ending to “ene”.
If there is a tie between longest chains, choose the chain that gives _____________ substituents.
2. Number the chain from the end closest to the double bond and provide a number for its location.
3. Substituents will be named alphabetically and a number will accompany the location of their attachment.
4. If more than one of a similar alkyl group is present then we must use numerical prefixes to describe the
number of them.
__________ – 2 __________ – 3 __________ – 4 __________ – 5
EXAMPLE 1: Naming the following alkene compound.
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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PRACTICE: NAMING ALKENES 1 EXAMPLE 2: Naming the following alkene compound.
EXAMPLE 3: Determine the structure for the following alkene compound.
5-bromo-4,4-dimethyl-2-heptene EXAMPLE 4: Determine the structure for the following alkene compound.
2, 5–octadiene EXAMPLE 5: Determine the structure for the following alkene compound.
Trans–3–hexene
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: NAMING ALKYNES Naming an alkyne is similar to naming an alkane with a few differences.
1. Find the longest carbon chain and change the “ane” ending to “yne”.
If there is a tie between longest chains, choose the chain that gives _____________ substituents.
2. Number the chain from the end closest to the triple bond and provide a number for its location.
3. Substituents will be named alphabetically and a number will accompany the location of their attachment.
4. If more than one of a similar alkyl group is present then we must use numerical prefixes to describe the
number of them.
__________ – 2 __________ – 3 __________ – 4 __________ – 5
EXAMPLE 1: Naming the following alkyne compound.
EXAMPLE 2: Provide the structural formula from the following alkyne name. 4–phenyl–2–nonyne
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: ALKANE REACTIONS Alkanes are also referred to as _______________, which is derived from Latin meaning “little affinity”.
This explains their very low reactivity.
Alkanes in general undergo only two main types of reactions.
a) _______________________________
b) _______________________________
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: FREE RADICAL CHAIN REACTION
As previously stated, alkanes are almost completely unreactive.
And one of the two reactions it undergoes is free-radical halogenation.
Under this reaction a ________________ on a carbon is replaced by a ________________.
The Radical Chain Reaction
Alkanes will react with diatomic halogens in the presence of __________________________________.
Initiation: (A stable compound undergoes homolytic cleavage: 0 free radicals 2 free radicals)
Propagation: (The radical reacts with a stable compound to create a new radical and new stable compound.)
Termination: (Two radicals join to create a stable compound: 2 free radicals 0 free radicals)
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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PRACTICE: FREE RADICAL CHAIN REACTION 1
EXAMPLE 1: Determine the major product(s) of the following reaction.
CH3CH3 + Br2
Heat or Light
EXAMPLE 2: Determine the major product(s) of the following reaction.
CH3CH2CH3 + Cl2Heat or Light
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: HALOGENATION
Alkenes and alkynes undergo addition reactions in which elements add across their ______
bonds to create new ______ bonds.
• Under Halogenation, ______ halogens are added to ______ pi bond.
EXAMPLE 1: Determine the major product from the following Halogenation reaction.
EXAMPLE 2: Determine the major product from the following Halogenation reaction.
CH3CH=CH2 + Cl2
+ 2 moles Br2
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: HYDROGENATION
Hydrogenation can be seen as a reduction reaction in which _____ hydrogens are added to _____ pi bond.
• In General Chemistry reduction is gaining _________ , but in Organic Chemistry
reduction is thought of as gaining ________________.
EXAMPLE 1: Determine the major product from the following Hydrogenation reaction.
EXAMPLE 2: How many moles of hydrogen would be needed to completely reduce the
following compound?
+ H2Catalyst
C CH
CH3
C
CH3
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: HYDROHALOGENATION
Under Hydrohalogenation, a _________________ and a _________________ are added across a pi bond.
1) Follows Markovnikov’s Rule
a) Hydrogen goes to the double bonded carbon with _______ hydrogens.
b) Halogen goes to the double bonded carbon with _______ hydrogens.
EXAMPLE 1: Determine the major product from the following Hydrohalogenation reaction.
EXAMPLE 2: Determine the major product from the following Hydrohalogenation reaction.
C CH
CH3
CH2CH2CH3
CH2CH3+ HCl
+ 2 moles HBrH3C C CH
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: AROMATIC REACTIONS Although benzene rings have pi bonds like alkenes and alkynes, they cannot undergo addition reactions because they are much too stable.
• We often refer to benzene as an aromatic compound in order to describe its high level of stability.
Instead of doing addition reactions benzene rings will under ________________ reactions in order to
maintain their aromaticity. The two major types of Aromatic reactions we will investigate will be:
1. _______________________________ – where a halogen is placed on benzene.
H
H
H
H
H
H
FeBr3+ Br2
H
H
H
H
H
H
FeCl3+ Cl2
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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2. _______________________________ – where an alkyl group is placed on benzene.
H
H
H
H
H
H
AlCl3+ CH3Cl
EXAMPLE 1: Determine the major product from the following Aromatic reaction.
H
H
H
H
H
H
AlBr3+Br
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: NOMENCLATURE OF FUNCTIONAL GROUPS Naming a compound with a functional group is similar to previous examples of naming we’ve done.
1. Find the longest carbon chain and change the “ane” ending based on the functional group present.
• If there is a tie between longest chains, choose the chain that gives _____________ substituents.
2. Number the chain from the end closest to the functional group present and provide a number for its location.
• Some functional groups don’t need their location numbered because they are terminal.
3. Substituents will be named alphabetically and a number will accompany the location of their attachment.
4. If more than one of a similar alkyl group is present then we must use numerical prefixes to describe the number
of them. __________ – 2 __________ – 3 __________ – 4 __________ – 5
Class Suffix Name Carboxylic Acid
-oic acid
Ester
-oate
Aldehyde
-al
Ketone
-one
Alcohol
-ol
Amine
-amine
Alkene
-ene
Alkyne
-yne
Alkane
-ane
Ether
ether
Alkyl Halide
---
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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PRACTICE: NOMENCLATURE OF FUNCTIONAL GROUPS 1 EXAMPLE 1: Provide the name of the following alcohols and alkyl halides and state if they are primary, secondary or tertiary.
a) BrCH2CH2CH2OH b)
CH3CH2CH2CH2CCH3
CH2CH3
OH
c) CH3CH2CH2CHCH3
Cl
EXAMPLE 2: Provide the name of the following functionalized organic compounds.
a) CH3COH
O
b) CH3CH2CH2CH2CH
O
c) CH3CH2CH2CH2CCH2CH3
O
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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PRACTICE: NOMENCLATURE OF FUNCTIONAL GROUPS 2
EXAMPLE 3: Provide the name of the following functionalized organic compound.
EXAMPLE 4: Provide the name of the following amines and state if they are primary, secondary or tertiary.
a) CH3CH2CH2CHCH2CH3
NH2
b) CH3CH2CH2NHCH2CH3
EXAMPLE 5: Provide the name of the following ethers
a) CH3CH2CH2OCH3 b) CH3CH2OCH2CH3
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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PRACTICE: NOMENCLATURE OF FUNCTIONAL GROUPS 3
EXAMPLE 6: Provide the structure of the following aromatic hydrocarbons. p-ethyltoluene EXAMPLE 7: Provide the structure of the following aromatic hydrocarbons. m-bromobenzoic acid EXAMPLE 8: Provide the structure of the following aromatic hydrocarbons. 2,4,6-trimethylnitrobenzene
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: ALCOHOL REACTIONS
Alcohols can be easily identified by the presence of the hydroxyl group ________ .
• Because of the presence of this highly polarized group alcohols can be involved in many organic reactions.
1. Substitution Reactions – under this reaction alcohols react with the hydrohalic acids of ______ or ______ to become alkyl halides.
CH3CH2CHCH2CH2CH3
OH
+ HBr
2. Elimination Reactions – under this reaction under the presence of concentrated acids such as __________ or __________ an alcohol undergoes dehydration to form an alkene.
CH3CCH3
OH
+ H2SO4
CH3
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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3. Oxidation Reactions – An alcohol can be seen as an alkane that has undergone an initial oxidation. The alcohol
can then continue to be oxidized to form either a(n) _________________ or _________________.
• This is done with the strong oxidizing agent sodium dichromate, Na2Cr2O7 and the strong acid sulfuric acid,
H2SO4.
• There is also an inverse relationship that can change our products back into their reactants.
CH3CCH3
OH
CH3
CH3CH2CHCH3
OH
CH3CH2CH2 OH H2SO4
Na2Cr2O7
H2SO4
Na2Cr2O7
H2SO4
Na2Cr2O7
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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TOPIC: CARBOXYLIC ACID DERIVATIVE REACTIONS Esters and amines are involved in reactions that deal with carboxylic acids.
1. Esterification – Under this reaction a carboxylic acid reacts with an alcohol and undergoes a dehydration reaction
in order to form an ester.
+ CH3CH2CH2OHHeatC
O
OH
2. Amide Formation – Under this reaction a carboxylic acid reacts with an amine and undergoes a dehydration to
reaction in order to form an amide.
+ CH3CH2NHCH3Heat
CH3CH2C
O
OH
CHEMISTRY - GILBERT 5E
CH.20 - ORGANIC AND BIOLOGICAL MOLECULES: THE COMPOUNDS OF LIFE
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