CHM 232 - IUPAC Naming Rules

Methane

1 carbon

Ethane

2 carbons

Propane

3 carbons

Butane

4 carbons

Pentane

5 carbons

Hexane

6 carbons

Heptane

7 carbons

Octane

8 carbons

Nonane

9 carbons

Decane

10 carbons

What is the first step of IUPAC naming?

count the number of carbon atoms in the parent chain

What is the parent chain?

The longest carbon chain

Which direction should you count in?

the direction where the substituent is assigned a lower number

Methyl

1 carbon

one single line coming of the parent chain

What do you use a hyphen for?

separating a number from a word

What do you use a comma for?

separating numbers from other numbers

di-

two

tri-

three

tetra-

four

What do you do if you have two substituents on the same carbon?

write the number of the carbon twice

e.g. 2,3,3-trimethylhexane

methyl

1 carbon substituent

ethyl

2 carbon substituent

propyl

3 carbon substituent

How should letters be alphabetized?

they need to be in alphabetical order

e.g. ethyl before methyl

How should numbers be ordered?

in ascending numerical order

When putting IUPAC names in alphabetical order, what should you ignore?

prefixes