Intro to Organic Reactions

Reactions of Alkanes

• They burn!

• Hydrocarbon and Oxygen yields Carbon Dioxide and Water

Reactions of AlkanesSubstitution Rxn

CH

H

HH

CH

Cl

HH

+ Cl2

UVlite

+ HCl

Reactions of AlkenesAddition Reactions

• Alkenes are Alkenes are unsaturatedunsaturated — more single bonds can form — more single bonds can form

to the C atomsto the C atoms

• Molecules such as BrMolecules such as Br22, H, H22, HCl, , HCl,

HBr, and HHBr, and H22O O addadd to the to the

double bonddouble bond

Addition Rxn

| | | |C = C + X2 - C - C - | | | | X X

X = Cl2, Br2, I2

Halogenation

An Addition Reaction

Fat Fat placed placed in Brin Br22

vaporvapor

Unsaturated Fats

An Addition Reaction

The fat in bacon is partially The fat in bacon is partially unsaturated. The fat adds Brunsaturated. The fat adds Br22

to the C=C bonds.to the C=C bonds.

Addition Rxn

| | | |C = C + H2 - C - C - | | | | H H

Ptcat

An Addition Reaction• Fats can be “hydrogenated” with HFats can be “hydrogenated” with H22..

Peanut butter has partially hydrogenated vegetable oil.

Peanut butter has partially hydrogenated vegetable oil.

Saturated Fats

Addition Rxn

| | | |C = C + HX - C - C - | | | | H X

H+

Addition Rxn

| | | |C = C + HOH - C - C - | | | | H OH

H+

Reactions of AromaticsReactions of Aromatics•SubstitutionsSubstitutions — not additions

— are typical.

AlClAlCl33 is a catalyst. Catalysts typically is a catalyst. Catalysts typically

used in aromatic substitutions.used in aromatic substitutions.

+ CH3Cl

CH3

+ HClAlCl3

Alcohol ReactionsAlcohol ReactionsScreen 11.6Screen 11.6

SubstitutionSubstitution Elimination—the Elimination—the reverse of reverse of additionaddition

TYPES OF ALCOHOLSTYPES OF ALCOHOLS

R C OH

H

H

R C OH

R

H

R C OH

R

R

CH3CH2OH, ethanol

rubbing alcohol H3C C OH

CH3

H

Primary

Secondary

Tertiary

More Alcohol ReactionsMore Alcohol Reactions

C

C

C

H H

H OH

HH

()

C

H O

H OH

H

()

Ethanol

+ Oxidizing agent

Acetic acid

+ Oxidizing agentC C

H O

H H

H

()

Acetaldehyde

Ethanol is a Ethanol is a PRIMARY PRIMARY ALCOHOLALCOHOL. It is . It is oxidized to an oxidized to an ALDEHYDE and then ALDEHYDE and then to an ACID.to an ACID.

More Alcohol ReactionsMore Alcohol Reactions

SECONDARY ALCOHOLS SECONDARY ALCOHOLS are are oxidized to KETONES — and oxidized to KETONES — and reaction stops there. reaction stops there.

R—C—R'

oxidizing agent

R—C—R'

O

Secondary alcohol KetoneH

(–R and –R' are organic groups. They may be the same or different.)

OH

Reduction of theCarbonyl GroupO

C

HR

H2cat CR OH

H

H

O

C

R'R

CR R'

H

OH

LiAlH4

aldehyde primary alcohol

ketone secondary alcohol

R C

OH

O

+ NaOH R C

O-Na+

O

+ HOH

Acid-Base Reaction

Acids + Alcohols ESTERS

Esters have generally pleasant odorsEsters have generally pleasant odors

R C

OH

O

R C

O

O

+ HOHR'HOH+

R'

Condensation Reaction

Acids + Alcohols ESTERS

H+

O O

CH3COH + CH3CH2OH CH3COCH2CH3 + H2O

Acetic acid Ethanol Ethyl acetate

C

OC

O O

H

O

CH3Aspirin, Aspirin, acetylsalicylic acid,acetylsalicylic acid,

Acid and EsterAcid and Ester

Acids + Amines AMIDES

Condensation Reaction

NH

HR'

R C

OH

O

R C

O

O

+ HOHH+

N

HR'

Acids + Amines Acids + Amines AMIDESAMIDES

N-methylacetamideN-methylacetamide

Acids + Amines AMIDES

AcetoaminophenTylenol, Datril, Momentum, ...

AcetoaminophenTylenol, Datril, Momentum, ...

C

C

C

C

C

C

H

H

N

H

O

HCC

O

H

HH

H

H

Amide link

H2N CH C

CH3

OH

O

H2N CH C

CH2

OH

O

OH

N CH C

CH2

OH

O

OH

H2N CH C

CH3

O H

-H2O

+

Amino Acid + Amino Acid Peptide

Alanine Serine

Peptide Bond

PolymerPolymerssPolymerPolymerss

• Giant molecules made by joining many Giant molecules made by joining many small molecules called small molecules called monomersmonomers

• Average production is 150 kg per person Average production is 150 kg per person annually in the U.S.annually in the U.S.

Polymer ClassificationsPolymer Classifications

• ThermoplasticsThermoplastics (polyethylene) soften (polyethylene) soften and flow when heatedand flow when heated

• ThermosettingThermosetting plastics — soft initially plastics — soft initially but set to solid when heated. Cannot but set to solid when heated. Cannot be resoftened.be resoftened.

• Other classification: Other classification: plastics, fibers, plastics, fibers, elastomers, coatings, adhesiveselastomers, coatings, adhesives

Polymer PreparationPolymer Preparation

•AdditionAddition polymers — directly polymers — directly adding monomer units togetheradding monomer units together

•CondensationCondensation polymers — polymers — combining monomer units and combining monomer units and splitting out a small water (water)splitting out a small water (water)

Polyethylene: Addition Polyethylene: Addition PolymerPolymer

H2C CH2 C C

H

H

H

H

n

n

EthyleneEthylene PolyethylenePolyethylene

A polymer with a molar mass A polymer with a molar mass of 1 x 10of 1 x 1066 has about 360,000 has about 360,000 units.units.

Mechanism of Addition Mechanism of Addition PolymerizationPolymerization

Types of PolyethyleneTypes of Polyethylene

Linear, high Linear, high density PE (HDPE)density PE (HDPE)

Branched, low Branched, low density PE, density PE, LDPELDPE

Cross-linked PE, Cross-linked PE, CLPECLPE

Types of PolyethyleneTypes of Polyethylene

CH2CH

OH

CH2CH

OCCH3

CH2CH

n n n

polyvinyl alcohol polyvinyl acetate polystyrene

Polymers based on Substituted Ethylenes, CH2=CHX

O

Table 11.12: others are PVC, Table 11.12: others are PVC, acrylonitrile, polypropylene, acrylonitrile, polypropylene,

polymethyl methacrylatepolymethyl methacrylate

C C

H

H

H

Cl

C C

H

H

C

H

Cl

C

H

H

C

Cl

H

C

H

H

C

H

Cl

C

H

H

C

Cl

H

C

H

H H

Cl

C C

H

H

C

H

Cl

C

H

Cl

C

H

H

C

H

H

C

Cl

H

C

H

Cl

C

H

H

C

H

H Cl

H

PolystyrenePolystyrene

• Polystyrene is nonpolar material and Polystyrene is nonpolar material and dissolves in organic solvents.dissolves in organic solvents.

• PS foam is mostly air, and when it dissolves PS foam is mostly air, and when it dissolves it collapses to a much smaller volume.it collapses to a much smaller volume.

Slime!Slime!

Slime is Slime is polyvinylalcohol polyvinylalcohol cross-linked cross-linked with boric acidwith boric acid

Bubble Bubble Gum!Gum!

A A copolymercopolymer

Bubble Bubble Gum!Gum!

A A copolymercopolymer

Styrene + butadieneStyrene + butadiene

Condensation PolymersCondensation Polymers

HOC

O

COH

O

CO

COCH2CH2OO

+ n HOCH2CH2OH

terephthalic acid ethylene glycol

+ H2O

Polyethylene terephthalate (PET), a polyester

n

n

Polyesters, PETPolyesters, PET

Jackets made from recycled PET soda

bottles

Soda Soda bottles, bottles,

mylar film.mylar film.

Polyesters: MechanismPolyesters: Mechanism

Polymer Recycling Polymer Recycling SymbolsSymbols

LDPE = LDPE = Low density PE = 0.910-0.925 g/cmLow density PE = 0.910-0.925 g/cm33

HDPE = HDPE = High density PE = 0.941-0.965High density PE = 0.941-0.965PP = PP = Polypropylene = 0.90Polypropylene = 0.90V = V = PVC (Vinyl chloride) = 1.30-1.58PVC (Vinyl chloride) = 1.30-1.58

CR OH

O

R’

H-N N-H

+C

O

OHH

H

- C - R - C - N - R’ - N -

O O

a POLYAMIDE

HH

Polyamides: NylonPolyamides: Nylon

•Each monomer has 6 C atoms in its chain.Each monomer has 6 C atoms in its chain.•A polyamide link forms on elmination of HClA polyamide link forms on elmination of HCl•Result = nylon 66Result = nylon 66

N CH C

CH2

*

O

OH

N CH C

CH3

O HH

Proteins are Polyamides

Fats and Oils: Fats and Oils: SaponificationSaponification

OO CR

OO CR

CH2

CH

CH2

OO CR

Glyceryl stearate, a fat + NaOH

R = —(CH2)16CH3

+ 3 NaOH

OH

OH

OH

+ 3 C

0

R O- Na+

Glycerol

sodium stearate (a soap)