How can I name hydrocarbons with functional groups?

1 Answer
Sep 24, 2014

Here are the IUPAC rules for naming simple organic compounds.

Rule 1: stem = name of alkane - "ane".
Rule 2: Locants (locating numbers) come immediately before the functional group or substituent, separated by hyphens with no spaces.
Rule 3: Omit locants if there is only one possible place for the functional group.

stem + "ene"; CH₃CH=CH₂ is propene; CH₃CH₂CH=CH₂ is but-1-ene

stem + "yne"; CH₃C≡CH is propyne; CH₃CH₂C≡CH is but-1-yne

Alkyl Groups
stem + "yl"; the carbon that attaches to the main chain is C-1 of the alkyl group.
CH₃CH₂CH₂- is propyl; (CH₃)₂CH- is 1-methylethyl (not 2-propyl)

stem of shorter chain + "oxy" + alkane name of longer chain (1 word)
CH₃OCH₂CH₃ is methoxyethane; CH₃CH₂OCH(CH₃)₂ is 2-ethoxypropane

"amino" + name of alkane (1 word)
CH₃CH₂NH₂ is aminoethane; CH₃CH₂CH₂NH₂ is 1-aminopropane

stem +"ol"; CH₃CH₂CH₂OH is propan-1-ol; CH₃CH(OH)CH₃ is propan-2-ol

stem + "al"; the carbonyl carbon is always C-1.
CH₃CH₂CHO is propanal; CH₃CH₂CH(CH₃)CHO is 2-methylbutanal

stem + "one; CH₃CH₂COCH₃ is butanone; CH₃CH₂CH₂COCH₃ is pentan-2-one

Carboxylic Acids
stem + "oic acid"; the carbonyl carbon is always C-1.
CH₃CH₂COOH is propanoic acid; CH₃CH₂CH(CH₃)COOH is 2-methylbutanoic acid

alcohol stem + "yl" acid stem + "oate"; the carbonyl carbon is always C-1.
CH₃COOCH₃ is methyl ethanoate; CH₃CH₂CH(CH₃)COOCH₂CH₃ is ethyl
2-methylbutanoate (two words)

acid stem + "amide"; the carbonyl carbon is always C-1.
CH₃CH₂CONH₂ is propanamide; CH₃CH₂CH(CH₃)CONH₂ is 2-methylbutanamide