Simple Organic ChemistryBasic Structure and

Nomenclature

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First Ten AlkanesFormula

Name Formula

Name

CH4 Methane C6H14 Hexane

C2H6 Ethane C7H16 Heptane

C3H8 Propane C8H18 Octane

C4H10 Butane C9H20 Nonane

C5H12 Pentane C10H22 DecaneAlkane = CnH2n+2

Straight Chain Alkanes aren’t “Straight”

CH3

CH3

C – C bonds are sp3 hybridized

Butane, C4H10

Structural Shorthand

H

H H

H

HH

H

H

HH

Explicit hydrogens (those required to complete carbon’s valence) are usually left off of drawings of hydrocarbons

CH3

CH3

Line intersections represent carbon atoms

C1 C1C2 C2

C3 C3C4 C4

Structural Isomers

CH3CH3

CH3

CH3 CH3

CH3

CH3

Isomers are molecules with the same chemical formula, but different organization of atoms (different bonding)

n-Pentane, C5H12

Isopentane, C5H12

Neopentane, C5H12

CH3 CH3

Newman Projections

A Eclipsed

E

Degrees of Rotation 30060 120 180 2400 360

B Staggered

HH

HH

HH

H

HH

H

H H

Ethane, C2H6

Rotation can occur around C – C single bonds

Newman Projections

Butane, C4H10 CH3

CH3

Cyclic AlkanesCyclopropane, C3H6

Remember, explicit hydrogens are left out

Cyclobutane, C4H8

Cyclopentane, C5H10

Cyclohexane, C6H12

Cycloheptane, C7H14

Rules for Naming Alkanes (Nomenclature)

For a branched hydrocarbon, the longest continuous chain

of carbon atoms gives the root name for the hydrocarbon

CH3

CH3

CH3

12 3

4

4 carbon chain = butane

Rules for Naming Alkanes (Nomenclature)

When alkane groups appear as substituents, they

are named by dropping the -ane and adding -yl.

CH3

CH3

CH3

—CH3 Methyl—CH2CH3 Ethyl—CH2CH2CH3 Propyl—CH2CH2CH2CH3 Butyl Methyl

Rules for Naming Alkanes (Nomenclature)

The positions of substituent groups are specified

by numbering the longest chain of carbon atoms

sequentially, starting at the end closest to the

branching.CH3

CH3

CH3

Methyl

12 3

4

Rules for Naming Alkanes (Nomenclature)

The location and name of each substituent arefollowed by the root alkane name. The

substituentsare listed in alphabetical order (irrespective of

anyprefix), and the prefixes di-, tri-, etc. are used

toindicate multiple identical substituents.

CH3

CH3

CH3

Methyl

12 3

4 Name:2-methylbutane

Nomenclature Practice

CH3 CH3

CH3

CH3

Cl

Name this compound

Step #1: For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon

152 43

9

6

87

9 carbons = nonane

Nomenclature PracticeName this compound

CH3 CH3

CH3

CH3

Cl

152 43

9

6

87

9 carbons = nonane

Step #2: When alkane groups appear as substituents, they are named by dropping the -ane and adding -yl.

CH3 = methylchlorine = chloro

Nomenclature PracticeName this compound

CH3 CH3

CH3

CH3

Cl

152 43

9

6

87

9 carbons = nonaneCH3 = methyl

chlorine = chloro

Step #3: The positions of substituent groups are specified by numbering the longest chain of carbon atoms sequentially, starting at the end closest to the branching.

1 9 NOT 9 1

Nomenclature PracticeName this compound

CH3 CH3

CH3

CH3

Cl

152 43

9

6

87

9 carbons = nonaneCH3 = methyl

chlorine = chloro

Step #4: The location and name of each substituent are followed by the root alkane name. The substituents are listed in alphabetical order (irrespective of any prefix), and the prefixes di-, tri-, etc. are used to indicate multiple identical substituents.

2-chloro-3,6-dimethylnonane

Alkenes Contain Carbon-Carbon

Double bonds

C C

H

H

H

H

Ethene

CC

H

H

H

H

1 bond

1 bond

Alkynes Contain Carbon-Carbon

Triple BondsC C HH

CC HH

Ethyne1 bond

1 bond

1 bond

Reactions of Alkenes and Alkynes

Hydrogenation323232 CHCHCHHCHCHCH Catalyst

Propene PropaneHalogenation

1-Pentene 1-2-dibromopentene322223222 CHCHBrCHBrCHCHBrCHCHCHCHCH

PolymerizationSmall molecules are joined together to form a large molecule

nCH2 CH2

Polyethylene

Aromatic Hydrocarbons

H

H

H

H

H

H

Cyclic unsaturated hydrocarbons with

delocalized electronsThe simplest aromatic hydrocarbon is

benzene (C6H6)H

H

H

H

H

H

OR…H

H

H

H

H

H

Geometric Isomerism in Aromatics

Cl

Cl

H

H

H

H

Cl

Cl

H

H

H

H

ortho (o-) = two adjacent substituents

meta (m-) = one carbon between substituents

para (p-) = two carbons between substituents

p-dichlorobenzene

o-dichlorobenzene

m-dichlorobenzeneCl

HH

H

Cl

H

Hydrocarbon DerivativesClass Functional Group General FormulaAlcohol hydroxyl group -O — H R – OHAlkyl halide — X R — XEther — O — R — O — R’Aldehyde carbonyl group O

|| — C — H

O || R — C — H

Ketone carbonyl group O || — C —

O || R — C — R’

Carboxylic acid carboxyl group O || — C —

OH

O || — C — OH

Ester O || — C — O—

O || R — C — O — R’

Amine amine group | —N—

R’ | R — N — R’’