By Mackenzie Venator, Graham Gourley, and David Petitpas Aldehydes and Ketones By Mackenzie Venator, Graham Gourley, and David Petitpas

of aldehydes and ketones! functional group composed of a ‘C’ double-bonded to an ‘O’. - Presence of a carbonyl group. - The carbon atom of the carbonyl group has two remaining bonds that can be filled by a hydrogen atom, an alkyl group, or an aryl group. General Structure of aldehydes and ketones!

When is it an aldehyde? When is it a ketone?

Aldehydes vs. Ketones - If at least one of the substituents on the open bonds of the carbon atom from the carbonyl group is a hydrogen atom, the compound is an aldehyde. - If instead of H’s, both substituents are aliphatic or aromatic, the compound is a ketone. - In simpler terms, carbonyl groups are located on an end carbon atom with aldehydes, but on one of the middle carbon atoms when dealing with ketones. An aldehyde. R represents an alkyl or aryl chain that differs depending on the molecule. A ketone. R and R’ indicate the possibility of having two different substituted groups.

de los aldehídos y cetonas! - Similar to the naming of alkanes, alkenes, and alkynes, the prefixes of aldehydes and ketones are based on the number of carbon atoms in the parent chain. - However, the suffix is different, as the -e of an alkane, alkene, or alkyne is replaced with an -al for an aldehyde and an -one for a ketone with the same amount of carbon atoms. ¡Nomenclature de los aldehídos y cetonas!

For example…

Other aldehyde naming rules - The carbonyl ‘C’ atom is given the #1 numbering location of the longest parent chain. - According to IUPAC, aldehydes use the same rules as alkanes regarding alkyl and aryl branches as well as other substituents (e.g. methyl, phenyl, chloro, dipropyl, cyclohexane). - For the common name of an aldehyde, start with the common parent chain name and add the suffix -aldehyde. Branch positions are indicated using Greek letters. - When the functional group is attached to a ring, the suffix becomes -carbaldehyde, and the carbon attached to that group is given location #1.

More examples of aldehydes

Ketone naming rules - Location numbering begins from the end closest to the carbonyl group. - Like aldehydes, ketones use the same rules as alkanes regarding alkyl and aryl branches as well as other substituents. - For the common name of an ketone, you simply list the substituent groups alphabetically before adding the word ketone.

- Uses for aldehydes and ketones can be both extracted from nature and produced in industry. Uses and Occurrences di aldeidi e chetoni!

Aldehyde Uses - Aldehydes tend to have pleasant odors, particularly those in which the R substituent group is aromatic. An example of this can be found in cinnamon, which gets its aroma from the aldehyde known as cinnamaldehyde. We also see examples of aldehydes in almond flavouring (benzaldehyde), pesticides (metaldehyde), and vaccines (formaldehyde).

Ketone Uses - Ketones can be found in steroid and sex hormones, like testosterone and progesterone. Carvone, a ketone, is found is spearmint, natural oils, and dill, and acetone (propanone following IUPAC) can be found in nail polish remover.

What happens when they react? Do they behave differently?

Oxidation De aldeidos e cetonas! - Aldehydes are very easily oxidised because their hydrogen atom makes them strong reducing agents. - Ketones lack the extra ‘H’, so they are more resistant to oxidation. - Only very strong oxidising agents, like potassium permanganate solutions, can oxidise ketones. Oxidation De aldeidos e cetonas!

Carboxylic acid formed Oxidation of aldehydes Carboxylate formed oxidation under acidic conditions oxidation under alkaline conditions Carboxylate formed

References Brady, James E. General Chemistry Principles and Structures 2nd edition. John Wiley & Sons, Inc. 1975. p.676-678. Hornback, Joseph M. Organic Chemistry. Brooks Cole. 2005. p.52. Libre Texts. <<Nomenclature of Aldehydes & Ketones>>. Sept272016. http://chem.libretexts.org/?title=Core/Orga nic_Chemistry/Aldehydes_and_Ketones/ Nomenclature_of_Aldehydes_%26_Keto nes

Photo credits Aldehyde structure – Slide 4 Ketone structure – Slide 4 Propane – Slide 6 Propanone – Slide 6 Propanal – Slide 6 2-Methylpropanal – Slide 8 3-Phenylpropanal – Slide 8 2,3-Dimethylpentanal – Slide 8 2-Chloro-3-phenylpropanal – Slide 8 4-Methylcyclohexanecarbaldehyde – Slide 8 2-Pentanone – Slide 9 Diethyl ketone – Slide 9 3-Ethyl-4-methyl-2-pentanone – Slide 9 Benzaldehyde – Slide 11 Almonds – Slide 11 Cinnamaldehyde – Slide 11 Cinnamon sticks – Slide 11 Metaldehyde – Slide 11 Metaldehyde pellets – Slide 11 Formaldehyde – Slide 11 Formaldehyde warning – Slide 11 Testosterone – Slide 12 Testosterone booster – Slide 12 Carvone – Slide 12 Spearmint – Slide 12 Acetone – Slide 12 Nail polish remover – Slide 12 Progesterone – Slide 12 Progesterone sample – Slide 12 Aldehyde structure – Slide 15 Carboxylic acid – Slide 15 Carboxylate – Slide 15