OCHEM Ch. 2 IUPAC Nomenclature

meth-

1 carbon prefix

eth-

2 carbon prefix

prop-

3 carbon prefix

but-

4 carbon prefix

pent-

5 carbon prefix

hex-

6 carbon prefix

hept-

7 carbon prefix

oct-

8 carbon prefix

non-

9 carbon prefix

dec-

10 carbon prefix

alkane

hydrocarbon with no carbon-carbon double or triple bonds

“-ane”

akyl substituents

• count the carbon atoms, use the correct prefix, and add “-yl”

• multiple substituents: list in alphabetical order

• multiple of the same substituent: use prefixes “di”, “tri”, “tetra”,”penta”

Fluro-

halogen substituents: fluorine (F)

Chloro-

halogen substituents: chlorine (Cl)

Bromo-

halogen substituents: bromine (Br)

Iodo-

halogen substituents: iodine (I)

alkene

molecule with at least one carbon-carbon double bond

“-ene”

alkyne

molecule with at least one carbon-carbon triple bond

“-yne”

cyclic alkane

“cyclo-”

spiro compounds

• compounds with two rings connected by a single carbon

• spiro[#,#]alkane

• count number of carbons in each ring except the spiro center, list numbers lowest to highest inside the bracket, what alkane parent chain name after the bracket

bicyclic compounds

• compounds with two or more rings linked together by two bridgehead carbons

• bicyclo[#,#,#]alkane

• count number of carbons in each ring excluding the bridgehead carbons, list numbers highest to lowest inside the bracket, write the alkane parent chain name after the bracket

cyclic carboxylic acid derivatives

• “-carboxylic acid”

• “-carboxamide”

ranking priority

1. carboxylic acid*

2. acid anhydride*

3. ester*

4. acid halide*

5. amide*

6. nitrile*

7. aldehyde

8. ketone

9. alcohol

10. amine

11. alkene

12. alkyne

13. alkyl, halogen, alkoxy, nitro

*carboxylic acid derivatives

carboxylic acid (-COOH)

• name the parent chain and number the carbons

• carbonyl carbon is always top priority

• “-oic acid”

acid anhydride (-CH₃CO)₂O

• list the components in alphabetical order without the word “acid”

• add “anhydride” at the end of the name

ester (-COOR)

• “-oate”

• alkyl group bonded to the ester oxygen has suffix “-yl”

acid halide (-COX)

“-oyl halide”

amide (-CONH₂)

“-amide”

• if alkyl groups are bonded to the amide nitrogen, they are specifiecd with the locant “N”

nitrile (-CN)

“-nitrile” after the “-e” ending of parent chain name

• don’t contain carbonyl group, but still considered carboxylic derivative

aldehyde (-CHO)

• highest priority suffix “-al”

• prefix “-oxo”

• bonded to hydrocarbon rings “carbaldehyde”

ketone (-C=O)

• highest priority suffix “-one”

• prefix “-oxo-”

alchol (-OH)

• highest priority suffix “-ol”

• prefix “-hydroxy”

amine (-NH₃)

• highest priority suffix “-amine”

• prefix “-hydroxy-”

• can be primary, secondary, or tertiary amine

ether (-ROR’)

• prefix “-alkoxy-”

nitro (-NO₂)

-prefix “-nitro-”

thiol (-SH)

• highest priority suffix “-thiol”

• prefix “mercapto-”

• can be primary, secondary, or tertiary amine

sulfonic acid (-SO₂H)

• highest priotiry suffix “sulfonic acid”

• suffix “sulfo”

sulfide (RST’)

prefix “alkylthio”

ethylbenzene

nitrobenzene

chlorobenzene

benzaldehyde

aniline (aminobenzene)

benzoic acid

toulene (methylbenzene)

anisole (methoxybenzene)

phenol (hydroxybenzene)

styrene (vinylbenzene)

multiple substituents on benzene

• higher priority substituent determines the name of the parent chain and is placed on carbon 1

  • the other substituents follow the usual nomenclature rules

guide to nomenclature

1. identify the parent chain (longest continuous carbon chain w/ highest/most substituents")

2. number the parent chain (lowest possible locants to priority functional groups and alphabetical substituents)

3. assemble full IUPAC name