Naming Unbranched Esters from Alcohols & Acids
Chemistry: Cambridge International GCSE Supplement, topic 11.2.3
Naming Unbranched Esters from Alcohols and Carboxylic Acids
Esters form from alcohols (-ol) and carboxylic acids (-anoic acid). Named as alkyl + oate, they contain a C=O and C-O-C link. Displayed formulae show these structures.
What are esters?
- Esters are organic compounds made from alcohols and carboxylic acids.
- Esters contain a carbon atom double-bonded to oxygen and single-bonded to another oxygen atom.
- The other oxygen is linked to an alkyl group from the alcohol.
Naming unbranched alcohols
- Unbranched alcohols have a straight chain of carbon atoms.
- Alcohol names end with "-ol"
- Examples include methanol (1 carbon), ethanol (2 carbons), propanol (3 carbons), butanol (4 carbons).
- Each name shows the number of carbons in the chain.
Naming unbranched carboxylic acids
- Unbranched carboxylic acids have a straight chain ending in COOH.
- Acid names end with "-anoic acid."
- Examples include methanoic acid, ethanoic acid, propanoic acid, butanoic acid.
- These acids have 1 to 4 carbon atoms in the chain.
Naming esters formed from alcohols and acids
- Esters are named: alkyl group from alcohol + acid name with "-oate" ending.
- For example, ethanol + ethanoic acid → ethyl ethanoate.
- The alkyl group name comes from the alcohol; the acid name changes "-anoic acid" to "-anoate".
- This rule applies to esters with up to 4 carbons in each part.
Drawing displayed formulae of unbranched esters
- To draw esters, link the alcohol alkyl group (C and H atoms) to the ester oxygen.
- Attach the acid part with a carbon double-bonded to oxygen and single-bonded to ester oxygen.
- For example, ethyl ethanoate has a 2-carbon group attached to oxygen and the acid part with 2 carbons.
- Practice drawing all combinations from 1 to 4 carbons on each part.
Test yourself on Naming Unbranched Esters from Alcohols & Acids
What is the ending for the name of an unbranched carboxylic acid?
When drawing the displayed formula of an ester, which part is linked to the single-bonded oxygen atom of the ester group?