Organic Chemistry

Hydrocarbons—Compounds that are only composed of hydrogen carbon

Saturated Hydrocarbons—DO NOT contain any pi bonds

IUPAC System—International; Union of Pure and Applied Chemistry


Number of Carbon Atoms

Parent

Name of Alkane

Number of Carbon Atoms

Parent

Name of Alkane

1

meth

Methane

11

undec

Undecane

2

eth

Ethane

12

dodec

Dodecane

3

prop

Propane

13

tridec

Tridecane

4

but

Butane

14

tetradic

Tetradecane

5

pent

Pentane

15

pentadic

Pentadecane

6

hex

Hexane

20

eicos

Eicosane

7

hept

Heptane

30

triacont

Triacontane

8

oct

Octane

40

tetracont

Tetracontane

9

non

Nonane

50

pentacont

Pentacontane

10

dec

Decane

100

hect

Hectane



Finding The Parent Chain

  • Pick the parent chain with the most substituents

  • If a parent chain is a cyclic (ring of carbons), you add the prefix “cyclo” to the beginning of the parent name

Identify Substituents (side groups)

  • Number in sequence of consecutive carbons in a parent chain

  • The number/locant is to communicate where each substituent is attached to the parent chain

Rules To Follow When Numbering The Parent Chain

  1. If one substituent is present, number the parent chain to give the substituent the lowest number possible

  2. When you have multiple substituents are present, number the parent chain to give the first substituent the lowest number possible

  3. If there’s a tie, then number the parent chain so that the second locant gets the lowest number possible

  4. If there is no tie breaker, then assign the lowest number by alphabetically

  5. Then assemble the complete name, assign a locant to each substituent, and lost them before the parent chain name in alphabetical order

  6. A prefix is used if multiple substituents are identical

    • Di

    • Tri

    • Tetra

    • Penta

  7. Prefixes are NOT used for alphabetical purposes, except for the prefix “iso”