Aldehydes and Ketones

pp. 212-213

Aldehydes and KetonesAldehydes

• Many essential oils belong to this group (almond, cinnamon bark, apricot oil, etc)

• Smaller aldehydes have stronger, less pleasant odours (antiseptics, preservatives, etc)

Ketones• Many pheromones

(chemical signals) found in this group

Aldehydes• Carbonyl group (C=O) at the end of a

carbon chain• General formula:

Naming AldehydesTake the parent name of the alkane and drop the ‘e’, to replace it with ‘al’.

Name the following aldehydes:

Structural Formulas for Aldehydes

Draw structural formulas for the following aldehydes:

butanal heptanal

Ketones• Carbonyl group (C=O) somewhere IN the

carbon chain. • General formula:

Naming KetonesTake the parent name of the (larger) alkane and drop the ‘e’, to replace it with ‘one’.

Name the following ketones:

Structural Formulas for Ketones

Draw structural formulas for the following ketones:

hexanone propanone

Properties of Aldehydes and Ketones

• Lower boiling point than alcohols, but higher than hydrocarbons (due to presence of C=O group)