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Organic Functional Groups
Chapter 7
Alcohols, Ethers and More
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What do you do when you are in Pain?
• What do you do when you are in a lot of pain?
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Functional Groups
• A functional group is an atom, groups
of atoms, or bond that gives a molecule
a particular set of chemical properties.
• Each family of organic compounds is
defined by the functional group that its
members contain.
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C-O
Containing
Functional
Groups
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Alcohols
All alcohols contain a hydroxyl (-OH)
functional group that is attached to an
alkane-type carbon atom.
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Alcohols
• Classification of alcohols is based on the degree of
substitution of the carbon they are attached to.
• Reactivity of alcohols is based on access.
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Naming Alcohols
• Drop the “e” ending on the name of the corresponding hydrocarbon
replacing with “ol.”
• The position of the -OH group must be specified with a number
similar to the double bond.
CH3
OH
H3C
H3C
CH3
Is 2-methylcyclohexanol a primary, secondary or tertiary alcohol?
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Properties of Alcohols
• Type of Intermolecular Forces present?
• Solubility in water?
• Boiling Point?
a. CH3CH2OH
b. HO-CH2CH2OH
c. . CH3CH3
d. CH3CH2CH2OH
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Polarity vs Chain Length
Octanol is insoluble in
water due to the long
nonpolar chain.
Methanol, ethanol and the
propanols are soluble in
water due to the polar -OH.
Properties of Alcohols
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Ethers
• An oxygen squeezed between carbons.
• The simplest will be having two methyl
groups attached.
• To name ethers:
• For simple ones name the groups in
alphabetical order followed by the word
ether.
• When other functional groups are present the
OR group has the ending –oxy as a
substituent. -OCH3 is methoxy.
• Solubility:
• Hydrophobic or hydrophilic?
• Polar or nonpolar?
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Carbonyl Containing
Functional Groups
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THE CARBONYL GROUP
• The carbonyl group is an oxygen double bonded to a
carbon.
• The carbon is connected to two groups or atoms.
• One of these may be an R group and the other may be
either an R group, a hydrogen or a heteroatom.
• The carbonyl group is not a functional group, but is a
component of functional groups shown on the following
slide.
Electronic
Geometry?
CARBONYL-CONTAINING GROUPS
All are polar.
Identify what is at each side of
the carbonyl.
Which ones have Hydrogen
bond?
Solubility in water?
Aldehydes and
Ketones
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Naming Aldehydes and Ketones
• When naming aldehydes and ketones the carbonyl (C=O)
must be part of the parent chain and receive the lowest
number.
• Since the carbonyl of an aldehyde is always in position
number 1, its position is not specified.
• For ketones, however, the position of the carbonyl must be
given, unless the molecule is small enough that there is no
question as to carbonyl placement.
• Parent chains are named by dropping the final “e” from the
name of the corresponding hydrocarbon and adding “al” for
aldehydes or “one” for ketones.
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Aldehydes and
Ketones
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What is the name?
O
CH3
H3C
CH3
a.
b.
c.
d.
e.
5-pentanone
2-pentanone
2-heptanal
3-ethylpentanone
3-ethyl-2-pentanone
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• Aldehydes and ketones have much lower
boiling points than alcohols with a similar
molecular weight.
• The differences in boiling points is due to the
fact that alcohols can form hydrogen bonds
while aldehydes and ketones cannot.
• The C=O is slightly polar, which allows an
aldehyde or ketone to interact with one another
through dipole-dipole forces.
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The polarity of the carbonyl
group and its ability to form
hydrogen bonds with water
molecules allows small aldehydes
and ketones to be highly water
soluble (“like dissolves like”).
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CARBOXYLIC ACIDS
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Carboxylic acids
contain a carboxyl
functional group,
which is the
combination of a
hydroxyl (-OH)
group and a
carbonyl (C=O)
group.
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Naming
• All the rules learned with the ending -oic acid.
• Carboxylic acids have priority number one in naming.
H3C
O
H3C
OH
CH3
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IONIZATION OF CARBOXYLIC ACIDS
• The carboxylic acid group may lose a proton (H+) in
solution to form the carboxylate ion. The name of the ion
ends in –ate ion, as indicated.
•Carboxylate ions are also much more soluble in water than
their carboxylic acid counterparts.
•What type of intermolecular force will be present?
FATTY ACIDS AND SOAP
• Remember that Fatty acids are long hydrocarbon chains
containing the carboxylic acid group.
• Soaps are the carboxylate form of fatty acids.
• The fatty acid portion of soap dissolves into greasy
materials, while the carboxylate portion attracts water,
explaining the cleaning action of soap.
HYDROGEN BONDING
• Carboxylic acids easily
form hydrogen bonds with
water or other similar
compounds.
•Small chains will be
soluble in water.
• Their hydrogen bonds
also increase their boiling
points.
What has the lowest boiling point?
a. CH3OCH3
b. CH3CH2OH
c. CH3CH2COOH
d. CH3COCH3
Functional Groups
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CARBOXYLIC ACID DERIVATIVES
• Carboxylic acid derivatives resemble carboxylic acids in
that they have a heteroatom connected to the carbonyl
group.
ESTERS and THIOESTERS
• Esters are similar to carboxylic acids except that –OR replaces –
OH.
•Thioesters are similar with an S
instead of the oxygen linking.
Identify all functional groups present
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AMIDES
• Amides consist of a nitrogen bonded to a carbonyl carbon.
• The nitrogen could have up to two hydrogens or R groups
attached.
•Naming:
• Count the carbons and use the ending –anamide.
•If the nitrogen is substituted named them as substituent starting
with the letter (N-) to indicate the position.
This image cannot currently be display ed.
N-methylethanamide
SOME COMMON AMIDES
• Proteins and oligopeptides contain the amide group.
• Penicillin is also an amide.
OTHER FUNCTIONAL GROUPS
Amines and Phosphates
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AMINES
• Amines are derived from ammonia (NH3) when
hydrogens are substituted by carbon compounds (R).
• What is the electronic geometry of ammonia?
•Molecular geometry?
• Amines are classified by the level of substitution:
AMINES ARE NOT AMIDES!
• Amines do not have a carbonyl group directly attached to
the N.
• This makes their properties entirely different.
• One property of amines is that they form ions; amides
cannot do this.
NAMING AMINES
• Each R group is treated like a usual substituent, and each ends with
a –yl.
• Following the substituent names in alphabetical order is the term
“amine.”
PHARMACOLOGICALLY ACTIVE NAMES
• Many amines have active biological properties.
• Amines derived from plants are called alkaloids.
• Some alkaloids are shown below.
HYDROGEN BONDING AND AMINES
• Amines easily
form hydrogen bonds.
• As before, these determine physical properties such as
boiling point and solubility.
AMINES COULD FORM IONS
• The nonbonding electrons on an amine nitrogen may
attract a proton to give the nitrogen a fourth bond.
• The resulting positively-charged
polyatomic ion is analogous
to the ammonium ion.
• These are soluble and
nature.
common in
AMINO ACIDS
• Amino acids contain both the amino group and the
carboxylic acid group.
• In neutral solution, both are charged.
• Amino acids are found in all proteins.
PHOSPHATES
• Phosphate esters are compounds derived from
phosphoric acid.
• All contain a P=O double bond and three P-O single
bonds. The oxygens in a phosphate ester are joined to up
to three R groups, replacing H’s.
• The phosphate is usually present as a polyatomic ion with
up to three negative charges.
CLASSES OF PHOSPHATE ESTERS
• The types of phosphate esters
depend on the number of R
groups present.
• In the di- or tri-phosphate
esters, the phosphate group is
also attached to an oxygen of the
next phosphate. This
structure is termed a
phosphoanhydride.
ATP
• ATP (adenosine triphosphate) is an example of a
triphosphate ester. It is the energy currency of the cell, used
as an intermediate in energy transfers.
• Note the presence of two phosphoanhydrides in ATP.
CHAPTER 7: Organic Functional Groups
PRACTICE PROBLEM
Epinephrine (adrenaline) is a hormone secreted when the body is under stress.
Illicit drugs that are structurally similar to epinephrine are highly addictive
stimulants. For example, the illegal and addictive drug methamphetamine is
similar in structure to epinephrine. However, pseudoephedrine, which is
structurally similar to epinephrine, is a decongestant and sold over the counter
in pharmacies.
a. Circle and label all the amine functional groups in these
molecules.
b. In what way is methamphetamine structurally similar to
pseudoephedrine? How is it different?
c. In the body, the amine in epinephrine is in its ionic form. Write
the structure of the ionic form of epinephrine.
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Compared to hydrocarbons with a
similar molecular weight, alcohols
have relatively high boiling points.
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