Naming Organic Compounds

alkane

a hydrocarbon in which all bonds are single bonds

alkene

a hydrocarbon that contains at least one carbon-carbon double bond

ethane

C2H6

ethene or ethylene

C2H4

meth-

Prefix for a one-carbon structure/chain

eth-

Prefix for a two-carbon structure/chain

prop-

Prefix for a three-carbon structure/chain

but-

Prefix for a four-carbon structure/chain

pent-

Prefix for a five-carbon structure/chain

hex-

Prefix for a six-carbon structure/chain

hep-

Prefix for a seven-carbon structure/chain

oct-

Prefix for a eight-carbon structure/chain

-ane

Suffix identifying compounds as alkanes

-ene

Suffix identifying compounds as alkenes

-yl

Suffix for simple alkyl groups (derived from alkane groups) that may be attached to straight chains

IUPAC Rules for Alkane Nomenclature

1. Find and name the longest continuous carbon chain.

2. Identify and name groups attached to this chain.

3. Number the chain consecutively, starting at the end nearest a substituent group.

4. Designate the location of each substituent group by an appropriate number and name.

5. Assemble the name, listing groups in alphabetical order. The prefixes di, tri, tetra etc., used to designate several groups of the same kind, are not considered when alphabetizing.

6.Have the general formula of CnH2n+2

IUPAC Rules for Alkene and Cycloalkene Nomenclature

1. The ene suffix (ending) indicates an alkene or cycloalkene.

2. The longest chain chosen for the root name must include both carbon atoms of the double bond.

3. The root chain must be numbered from the end nearest a double bond carbon atom. If the double bond is in the center of the chain, the nearest substituent rule is used to determine the end where numbering starts.

4. The smaller of the two numbers designating the carbon atoms of the double bond is used as the double bond locator. If more than one double bond is present the compound is named as a diene, triene or equivalent prefix indicating the number of double bonds, and each double bond is assigned a locator number.

5. Have the general formula of CnH2n

Methane

CH4

Propane

C3H8

Butane

C4H10

Penatne

C5H12

Hexane

C6H14

Heptane

C7H16

Octane

C8H18

Propene

C3H6

1-Butene

C4H8

1-Pentene

C5H10

1-Hexene

C6H12

1-Heptene

C7H14

1-Octene

C8H16