Ketones feature the carbonyl group (C=O) bonded to two alkyl groups, symbolized as \text{R-CO-R'}. Unlike aldehydes, the carbonyl carbon is not at the end of the carbon chain. With the molecular formula \(\text{C}_5\text{H}_{10}\text{O}\), possible ketone structures are:
- \(\text{CH}_3-\text{CO}-\text{CH}_2-\text{CH}_2-\text{CH}_3\) (pentan-2-one)
- \(\text{CH}_3-\text{CH}_2-\text{CO}-\text{CH}_2-\text{CH}_3\) (pentan-3-one)
- \(\text{CH}_3-\text{CO}-\text{CH}(\text{CH}_3) -\text{CH}_3\) (2-methylbutan-2-one)