FUNCTIONAL GROUPS
ORGANIC HALIDES
Properties
• Halogen makes the molecule more polar,
increasing strength of the intermolecular
forces
– Higher boiling points than their corresponding
hydrocarbons
– More soluble in polar solvents
• Molecules with more halogens are more polar
Preparing Organic Halides
Recall: Substitution reaction produce halides in alkanes
and aromatic hydrocarbons
Preparing Organic Halides
Recall: alkyl halides are produced in halogenation reactions
(addition) with alkenes/alkynes
Elimination Reactions
• Preparing alkenes from alkyl halides
• Most common method of preparing alkenes
• Alkyl halides can eliminate a hydrogen and a halide ion from
adjacent carbon atoms forming a double bond.
• Presence of a hydroxide ion is required
ALCOHOLS
• Organic compounds containing a hydroxyl group -OH
• E.g. ethanol, cholesterol, retinol (vitamin A)
Naming:
• -ol suffix e.g. methane + OH = methanol
Polyalcohols
• Alcohols containing more than one -OH group
• -diol, -triol suffix
• Or hydroxy prefix
1,2-dihydroxyethane
1,2,3-trihydroxypropane
Properties of Alcohols
• More polar and can hydrogen bond
• Higher boiling points
• More soluble in polar solvents
• Long-chain alcohols are nonpolar (hydrocarbon
portion) and polar (-OH)
• Ideal solvents in organic reactions because they will
dissolve both polar and nonpolar compounds
REACTIONS INVOLVING ALCOHOLS
Hydration Reactions (Addition)
(Formation of Alcohol)
• Alkene + water --> alcohol
• Follows Markovnikov’s rule
Combustion of Alcohols
Elimination Reactions
Dehydration (Condensation) Reactions:
• Under certain conditions alcohols can decompose to
produce alkenes and water
• A catalyst (sulfuric acid) removes a hydrogen atom and a
hydroxyl group from neighbouring carbons
• Resulting in C=C and H2O
ETHERS
• Molecules with C-O-C group
• More polar than hydrocarbons
• But, unlike alcohols, ethers cannot hydrogen bond
Naming:
• Add oxy to the prefix of the smaller hydrocarbon group
and join it to the alkane name of the larger hydrocarbon
group
• E.g. CH3-O-C2H5 is methoxyethane
Condensation Reactions
(Formation of Ethers)
• When two alcohols combine, an ether and water are formed
ALDEHYDES AND KETONES
Ketone: Molecule with a carbonyl group (C=O) between two
carbon atoms. Alkane name with -one suffix
Aldehyde: Molecule with a carbonyl group (C=O) on a terminal carbon.
Alkane name with -al suffix
Properties of Aldehydes and Ketones
• Polar but no Hydrogen Bonding
• Lower boiling point and less soluble in water than alcohols (no -OH)
• More polar than hydrocarbons (higher boiling points and more
soluble)
• Good solvents (both polar and nonpolar)
Oxidation Reactions
• Alcohol + an oxidizing agent (removes
electrons) to form an aldehyde or ketone and
water
• The oxidizing agent removes two H-atoms
(one from the -OH group and one from the
adjacent carbon) resulting in C=O and H2O
Oxidizing agent
No
available
H-atom
Hydrogenation Reactions
• The C=O double bond can undergo an addition reaction with
hydrogen to form an -OH group.
• Aldehydes always produce 1˚ alcohols
• Ketones always produce 2˚ alcohols
CARBOXYLIC ACIDS
• Molecules with a carboxyl group -
COOH
• E.g. lactic acid, citric acid
• NAMING:
• Alkane name with -oic acid
• E.g. methanoic acid
Properties of Carboxylic Acids
• Polar
• Can hydrogen bond
• Similar properties to alcohols (smaller
members are soluble in water, larger
members are insoluble)
• pH < 7 (H-atom in -OH group)
Oxidation Reactions
Recall: A 1˚ alcohol can be oxidized to form an aldehyde.
An aldehyde can be further oxidized to form a carboxylic acid
A ketone cannot be oxidized because there is no free H-atom
Oxidation Reaction
ESTERS
• NAMING:
• 1st name is the part single
bonded to only 1 Oxygen
(the part that was originally the alcohol)  it gets
named like a side chain with the ending ‘-yl’
• 2nd name is the part double bonded to the
Oxygen  it is named with the ending ‘-oate’
EXAMPLES
Esterfication (Formation of Esters)
Recall: acid + base --> salt + water (neutralization reaction)
Carboxylic acid + alcohol --> ester + water
Properties of Esters
• Similar to carboxylic acids, but lacking -OH group
• Esters are less polar (less soluble in water), lower boiling
points (no H-bonds)
• Not acidic
•Many have characteristic scents
AMINES
• An ammonia molecule in which one or more H-atoms are
substituted by alkyl or aromatic groups
Naming:
• Amino + alkane name OR
• Alkyl group + amine
Naming 2˚ and 3˚ Amines
• N- prefix used for the substituted groups on the nitrogen
atom
• Alkyl groups are listed alphabetically
N,N-dimethyl-2-aminopropane
Properties of Amines
• N-C, and N-H polar bonds
• H-bonding occurs but N-H is less polar than O-H
Synthesizing Amines from Alkyl Halides
• Alkyl halide + ammonia --> 1˚ amine + HX
• Alkyl halide + 1˚ amine --> 2˚ amine + HX
• Alkyl halide + 2˚ amine --> 3˚ amine + HX
Synthesizing Amines from Alkyl Halides
AMIDES
• Similar to esters, except N instead of O
Recall: Carboxylic acids + alcohols --> esters + water
Carboxylic acids + ammonia/1˚/2˚ amines--> amides + water
Naming Amides
• 1st part is the name is from the amine
• 2nd part is the ending of the acid name changed from -oic to
-amide
• Alphabetical order with N- groups
N-ethyl propanamide
Summary