Naming Organic Compounds

IUPAC naming purpose

Provides systematic names for organic compounds

Longest chain rule

Base name comes from longest continuous carbon chain

1 carbon chain

Meth‑

2 carbon chain

Eth‑

3 carbon chain

Prop‑

4 carbon chain

But‑

5 carbon chain

Pent‑

6 carbon chain

Hex‑

7 carbon chain

Hept‑

8 carbon chain

Oct‑

Alkane suffix

‑ane

Alkene suffix

‑ene

Alcohol suffix

‑ol

Carboxylic acid suffix

‑oic acid

Functional group priority

Functional group determines suffix and numbering direction

Numbering rule

Number from end giving lowest number to functional group

Position number use

Insert number before suffix (e.g., but‑2‑ene)

Side chain definition

Branch off main carbon chain

Side chain name

Methyl, ethyl, propyl, etc.

Side chain position

Number carbon where branch attaches

Multiple side chains

Use prefixes di‑, tri‑, tetra‑

Alphabetical order rule

Side chains listed alphabetically

Isomer definition

Same molecular formula, different structure

Structural isomers

Different arrangement of atoms

Position isomers

Functional group in different positions

Key idea

Identify longest chain → locate functional group → number chain → add side chains