Download reactions of organic compounds

REACTIONS OF ORGANIC
COMPOUNDS
Textbook: Chapter 2
Cancer and TAXOL
Read page 56 of your text and answer the
following:
1. What is TAXOL? Where is it found?
2. What was so exciting about the discovery of
the compound in the European yew?
3. Explain why the study of organic chemistry is
really the study of functional groups.
The Main Types of Organic Reactions
•
•
•
•
•
•
•
Addition
Substitution
Elimination
Oxidation
Reduction
Condensation
Hydrolysis
Addition
• Atoms are added to a double or triple bond
– (decrease in multiple bonds)
• Two compounds usually react to form one
major product.
Substitution
• Hydrogen atom or a functional group is
replaced by a different functional group.
• Two compounds usually react to form two
different products.
Elimination
• Atoms removed from a molecule to form a double
bond.
• Reverse of addition.
• More multiple bonds
• One reactant usually breaks up to form two
products.
Oxidation
• In organic chemistry, oxidation is a reaction in
which a carbon atom forms more bonds to
oxygen or less bonds to hydrogen.
– (Increase C-O or decrease C-H).
Reduction
• Carbon atoms forms fewer bonds to oxygen,
O, or more bonds to hydrogen, H.
– Less C-O or C-C bond. (ex// C=O to C-O).
• Opposite of oxidation.
Condensation
• Two organic molecules combine to form a
single organic molecule.
• Water is usually produced.
Hyrolysis
• Reverse of condensation
• Water is added to a bond, splitting the organic
molecule into two.
Classifying Reactions
• Complete the following table. This is to help
you identify different kinds of reactions easier!
General Change
Reactants:
Products
Specific Change
2:1
Less multiple
Addition
bonds/more H
or functional
groups around C
1:2
More multiple
Elimination
bonds/less H or
functional
groups around C
...
...
Change in C-C
bonds
...
Type of
Reaction
...
Example
...
Identifying Reactions
• PP pg. 63
2.1 Homework
Page 63, # 1 b,c. #2 b, c. #3 b. #4 b.
SR, page 64, #1 - 5
2.2 Reactions of Functional Groups
Alkenes and Alkynes have ____________ or
________ bonds. Multiple bonds are more
____________ than single bonds.
• Alkenes and Alkynes undergo addition
reactions involving:
– H and OH (from water)
– H and X (from XH) where X=Cl, Br, or I.
– X and X (from X2) where X=Cl, Br, or I.
– H and H (from H2).
Symmetry of Reactants
• The product of an addition reaction depends
on the symmetry of the reactants.
– Symmetrical alkene: identical groups on either
side of double bond. E.g. Ethene:
– Asymmetrical. E.g. Propene.
• Added molecules can also be
symmetrical/assymetrical.
– Symmetrical: E.g. Chlorine.
– Asymetrical: E.g. Water.
What do you notice about these reactions?
_______________________________________
_____________________________________
_____________________________________
What do you notice about this reaction?
_______________________________________
_____________________________________
_____________________________________
Markovnikov’s Rule
• Used when the products are two isomers.
• Determines which isomer will be most
prominent (only a small amount of other
isomer will be produced).
• MARKOVNIKOV’s RULE: the halogen atom or
OH group in an addition reaction is usually
added to the carbon bonded to the most
carbon atoms.
Determining the Product of a Reaction
PP, page 67.
Addition to Alkynes
• Since alkynes have triple bonds, _________ addition reactions
can take place in a row.
• If one mole of a reactant, such as HCl, Br2, or H2O is added to
one mole of an alkyne, the result is a substituted alkene.
• If two moles of the reactant are added to one mole of an
alkyne, a second addition reaction takes place, producing an
alkane.
Markovnikov’s Rule and Alkynes
Asymmetrical alkynes follow M.’s rule. when an
asymmetrical molecule is added to the triple bond.
Note: the halogen is bonded to the carbon around the
triple bond that is bonded to the most carbons. The
hydrogen is bonded to the carbon around the triple
bond that has the most hydrogens.
THE RICH GET RICHER!
Reactions of Aromatic Compounds
• Benzene’s stable ring does not usually accept
the addition of other atoms.
• Aromatic compounds undergo substitution.
• Addition reaction does not occur because the
product of this reaction would be less stable
than benzene.
Reactions of Alcohols
• Substitution Reactions of Alcohols
– When a Halogen acid, such as HCl, HBr, or HI,
reacts with an alcohol, the halogen atom is
substituted for the OH group of alcohol.
– An alcohol is a product when an alkyl halide reacts
with OH- in a basic solution.
• Elimination Reactions of Alcohols
– When an alcohol is heated in the presence of a
strong acid and dehydrating agent, H2SO4,
elimination reaction occurs.
• Oxidation of Alcohols
- In the presence of an oxidizing agent, an alcohol is oxidized to form
an aldehyde or ketone.
- A primary alcohol is oxidized to an aldehyde. If the aldehyde is oxidized further,
it becomes carboxylic acid.
- A secondary alcohol is oxidized to a ketone. (Can a further oxidation occur?)
- A tertiary alcohol cannot be oxidized.
PP pg. 73 #9-13.
Oxidation of Aldehydes and Ketones
• Aldehydes and ketones react differently with
oxidizing and reducing agents.
Oxidation of Aldehydes
In the presence of
oxidizing agent, aldehydes will become
carboxylic acids.
Oxidation of Ketone
Like tertiary alcohols, ketones do not have a
Hydrogen atom available to be removed.
C-C bonds are too strong to be broken by an
oxidizing agent.
Reduction of Aldehydes and Ketones
• Aldehydes are reduced to produce primary alcohols.
• Ketones are reduced to produce secondary
alcohols.
Reactions of Carboxylic Acids
• Like other acids, carboxylic acid reacts with a base to produce a
salt and water.
• A carboxylic acid reacts with an alcohol to produce an ester. A
strong acid (e.g. Sulfuric acid) catalyzes the reaction.
– ESTERIFICATION REACTION!  SPECIAL CONDENSATION REACTION.
Reactions of Esters and Amides
• Both undergo hydrolysis reactions.
• Hydrolysis of an ester produces a carboxylic acid and
an alcohol.
• The hydrolysis of an amide produces a carboxylic acid
and an amine.
• Hydrolysis can be acidic or basic hydrolysis.
– In acidic: org. Mol. Reacts with water in the presence of an
acid.
– In basic: org. Mol. Reacts with OH- ion, from base or water
in the presence of a base.
SOAP IS MADE BY THE BASIC HYDROLYSIS OF ESTER ONDS IN
OILS OR FATS.
Concept Organizer
PPs, pg. 78, #14-17
SR, pg. 79, #1-8.
2.3 – Molecules on a Larger Scale:
Polymers and Biomolecules
• For the most part, we have seen small organic
molecules so far.
• Many of the organic molecules that are used
industrially, such are plastics, are large organic
molecules.
POLYMER: very long molecule made by linking
together many smaller ‘building blocks.’
MONOMER: the ‘building blocks.’
(PAPER CLIPS)
Synthetic Polymers
• Plastics: polymers that can be heated and
moulded into specific shapes and forms.
– Polyethene: plastic bags.
• Adhesives, rubber, chewing gum, and
styrofoam.
Natural Polymers
• Glucose, _____________, is the monomer for
the natural polymer _____________.
Fabrics
• Some polymers can be spun into long, thin
fibres.
• Fibres woven into natural fabrics (cotton,
linen, and wool) or synthetic fabrics (rayon,
nylon, and polyester).
Names of Polymers
• Polymers are formed by either addition and
condensation reactions.
• The name of a polymer is usually written with
the prefix poly-. (polyethene).
• The common name of the monomer is often
used rather than the IUPAC name. (the
common name of ethene is ethylene.
Therefore, polyethene is often called
polyethylene).
Addition Polymerization
• Monomers with double bonds joined together
through multiple addition reactions to form a
polymer.
Examples of Addition Polymers
Condensation Polymerization
• Monomers are joined together by the
formation of ester or amide bonds.
• Water is usually produced.
• Each monomer must have two functional
groups.
• Ester Bonded Polymers: polyesters. From
esterification or diacids and dialcohols.
• Amide Bonded Polymers: nylons or
polyamides.
PPs, pg. 84. #18-21
Natural Polymers
• Synthetic polymers have been made by
imitating natural polymers.
• Biochemistry: study of organic compounds
and reactions that occur in living things.
• Important natural polymers:
_________________, __________________,
___________________, __________________.
Amino Acids and Proteins
Proteins: composed of monomers called
_________________.
Found in meat, milk, eggs, and legumes and make
up wool, leather, and silk. Fingernails, hair, and
skin are composed of different proteins.
Three functions of proteins within our bodies are:
__________________________,
_________________________, and
______________________________.
Amino Acids
- 20 common amino acids  all containing a
carboxylic acid group and an amino group.
- each amino acid has a different side chain,
which is attached to the center carbon atom.
• Amino acids –> Protein
• Aas linked by amide
bonds to form
polymer.
• Shape and biological
function of protein
depends on sequence
of amino acids.
– Insulin: more than 50
amino acid groups.
– Infinite number of
proteins are possible.
– DNA contains
blueprints for making
specific proteins.
Carbohydrates
• Also called a ‘saccharide’ – contains either an
aldehyde or ketone group with two or more
hydroxyl groups.
• C=O group reacts with OH group within linear
structure to form a ring in most cases (in
monomer)
• Common monomers are glucose and fructose.
• Carbs found in bread, pasta, potatoes and fruits.
• Primary source of energy – used in cellular
respiration.
• Monosaccharide: simple carbohydrate, or
simple sugar.
• Disaccharide: contains two monosaccharides.
– -OH group on one monomer reacts with –OH
group on another monomer to form an ether –Olinkage: special kind of __________________.
• Polysaccharide: many saccharide units
(monomers).
– Glucose polysaccharides:
– Cellulose: plant structural material.
– Starch: plant energy storage material.
– Glycogen: animal energy storage.
Nucleotides and Nucleic Acids
• Nucleic Acids: DNA and RNA
– DNA – found mostly in nuclei of cells.
– Each strand of DNA is a polymer composed of
repeating units called nucleotides.
– One DNA strand may have more than one million
nucleotides.
– RNA – works closely with DNA to produce
proteins.
Lipids
• Not polymers, but very large.
• Not soluble in water, but are soluble in other nonpolar solvents.
– Large hydrocarbon parts, therefore,
_________________________.
– Fats, oils, waxes.
• Fats: one glycerol ester linked three long-chain carboxylic
acids. Solid at room temp.
• Oils: same structure, but liquid at room temp.
• Waxes: esters of long-chain alcohols and long-chain
carboxylic acids.
• Lipid function:
– Long-term storage of energy.
– One gram of fat contains 2.25 X more energy than one
gram of carb or protein.
– If more carbohydrates are consumed than needed,
body converts excess to fat  broked down when
needed.
– Cell membranes.
– Hormones (cholesterol, testosterone).
– Vitamins.
– Insulation and packaging.
SR. Pg. 95. #1 – 5.
Homework
All PPs and SRs outlined in this Lecture.
Read the section “Risks of the Polymer Industry”
on page 88 and make short notes.
Read the Chemistry Bulletin on Page 89 and
make short notes. Answer questions 1-3.
THIS HAS BEEN UPDATED. REFER TO THE
HANDOUT, ‘THE POLYMER INDUSTRY.’
Notice/Review (UPDATED)
Organic Chemistry Unit Test on WEDNESDAY (April 27)
Suggested Review:
•
Read over Intermolecular Forces section on page 23.
Use this knowledge to create a concept map
outlining the Physical Properties of all functional groups
we’ve looked at (in tables throughout ch. 1).
• Ch. 1 Review (pg. 52):
– Know all key terms.
– # 1, 3 – 14, 15-16, 21, 22.
• Ch. 2 Review (pg. 105)
– Know all key terms.
– # 1-11, 13-17, 18-20 (every second one), 21.
• Unit 1 review: 1-16, 20, 21, 23, 28, 30-31, 32, 34, 36-40 (every
second one),