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Types of Organic Reactions

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Types of Organic Reactions
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
Types of Organic Reactions
Learning Goal:
I will understand the different kinds of organic
reactions (addition, elimination, substitution,
condensation, esterification, hydrolysis, oxidation,
reduction, combustion) and be able to recognize each,
as well as show the products/reactants of each type of
organic reaction
UNIT 1 Chapter 2: Reactions of Organic Compounds
Summary of Organic Reactions
Important types of organic reactions:
• addition
• elimination
• substitution
• condensation
• esterification
• hydrolysis
• oxidation
• reduction
• combustion
Section 2.1
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
Recap: Addition Reactions
•
•
•
•
Reactions between an alkene or alkyne and a small
molecule (HOH, H2, HX, X2)
Atoms of a small molecule are added to carbons of a
double or triple bond
Reactions of alkynes can produce alkenes or alkanes
Constitutional isomers may form
Carbon atoms of the
multiple bond have more
atoms bonded to them in
the product.
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
LEARNING CHECK #1
Show how constitutional isomers can
form from the following reaction.
Answer on
the next slide
UNIT 1 Chapter 2: Reactions of Organic Compounds
LEARNING CHECK #1: ANSWER
The chlorine atoms can be added to
either carbon 2 or 3 in this addition
reaction.
Section 2.1
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
Addition Reactions (cont’d)
One constitutional isomer will predominate.
To predict the major product:
Markovnikov’s rule:
The hydrogen atom of the small molecule will attach to the
carbon atom of the double bond that is bonded to the most
hydrogens.
The 2-chloropropane
isomer will be the
major product.
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
Elimination Reactions
•
•
•
Two atoms bonded to carbon atoms of an organic
molecule are removed and a double bond forms
The double bond forms between the carbon atoms that
have had the atoms removed
Elimination reaction can be thought of as the reverse of
an addition reaction
Carbons of the organic
product are bonded to
fewer atoms than carbons
of the reactant.
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
LEARNING CHECK #2
Draw the product of the following
elimination reaction.
Answer on
the next slide
UNIT 1 Chapter 2: Reactions of Organic Compounds
LEARNING CHECK #2: ANSWER
The product formed is:
Section 2.1
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
Elimination Reactions (cont’d)
What if an asymmetric molecule undergoes elimination?
General rule:
The hydrogen atom is more likely to be removed from the
carbon atom with the most C-C bonds.
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
Substitution Reactions
•
•
•
Reaction in which a hydrogen or functional group has
been replaced by another functional group
Two compounds react to form two different compounds
The same number of atoms are bonded to the carbon
atoms of the reactants and products
Two compounds are
converted to two new
compounds.
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
LEARNING CHECK # 3
Draw the products of the following
substitution reaction.
Answer on
the next slide
UNIT 1 Chapter 2: Reactions of Organic Compounds
LEARNING CHECK # 3: ANSWER
The products formed are:
Section 2.1
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
Condensation Reactions
•
•
•
•
Two molecules combine to produce a larger organic
molecule and another much smaller molecule
Water is often the smaller molecule formed
Large biomolecules (DNA, fats, carbohydrates, protein)
are formed through this type of reaction
Production of amides and esters are examples
A condensation reaction
between a carboxylic acid
and an amine produces
an amide.
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
Esterification Reactions
(A type of condensation reaction)
•
•
These are a type of condensation reaction
A carboxylic acid and an alcohol react to produce an
ester and water
In what way(s) is an esterification reaction like a
condensation reaction?
An esterification reaction
is between a carboxylic
acid and an alcohol.
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
Hydrolysis Reactions
•
•
•
A molecule is broken apart through the addition of a
water molecule (HOH)
The –OH is added to one side of a bond, and the H is
added to the other side of the bond
They are the reverse of condensation reactions
In hydrolysis reactions,
molecules are broken
apart using water as a
reactant.
Hydrolysis Reactions are the Reverse of
a Condensation Reaction
UNIT 1 Chapter 2: Reactions of Organic Compounds
LEARNING CHECK #4
Section 2.1
What are the products of the following
reaction? What type of reaction is this?
Answer on
the next slide
UNIT 1 Chapter 2: Reactions of Organic Compounds
LEARNING CHECK #4: ANSWER
This is an esterification reaction.
The products are:
Section 2.1
LEARNING CHECK #5
The hydrolysis reaction with water is so slow that must be
catalysed with dilute acid, so the ester is heated with a dilute
acid like dilute hydrochloric acid or dilute sulphuric acid.
Show/name the products of hydrolysing ethyl ethanoate:
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
Oxidation Reactions
• In organic chemistry, the term refers to carbon atoms of
the organic reactant
• forming more bonds to oxygen atoms, or
• forming fewer bonds to hydrogen atoms
•
Common oxidizing agents, [O], are KMnO4 and
K2Cr2O7
Compare the number of C-H and C-O bonds in the reactant and product.
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
Reduction Reactions
• In organic chemistry, the term refers to carbon atoms of
the organic reactant
• forming fewer bonds to oxygen atoms, or
• forming more bonds to hydrogen atoms
•
Common reducing agents, [H], are LiAlH4 and H2/Pt
Compare the number of C-H and C-O bonds in the reactant and product.
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
LEARNING CHECK #6
What is the product of the following
reaction? Is this an oxidation or
reduction reaction?
+ [H]
Answer on
the next slide
UNIT 1 Chapter 2: Reactions of Organic Compounds
LEARNING CHECK #6: ANSWER
The reaction is a reduction of propanone (acetone)
to produce propan-2-ol (isopropanol). There are
fewer bonds to O, and more bonds toH
Section 2.1
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
Combustion Reactions
•
•
•
A compound reacts with oxygen to produce oxides of
the component elements
The products of the complete combustion of a
hydrocarbon are carbon dioxide and water
If O2 is insufficient, incomplete combustion occurs
UNIT 1 Chapter 2: Reactions of Organic Compounds
Organic Reactions Summary
Section 2.1
UNIT 1 Chapter 2: Reactions of Organic Compounds
Section 2.1
HOW DID WE DO?
Learning Goal:
I will understand the different kinds of organic
reactions (addition, elimination, substitution,
condensation, esterification, hydrolysis, oxidation,
reduction, combustion) and be able to recognize each,
as well as show the products/reactants of each type of
organic reaction
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