Aldehydes and Ketones

1. Aldehydes and Ketones • In an aldehyde, a carbon group and an H atom is attached to a carbonyl group O carbonyl group  CH3 - C -H carbonyl group always joined to at least one hydrogen (meaning it is always on the end!)

2. Aldehydes and Ketones • In a ketone, two carbon groups are attached to a carbonyl group O carbonyl group  CH3- C -CH3 carbon of the carbonyl group is joined to two other carbons (meaning it is never on the end)

3. Naming Aldehydes • IUPAC Replace the -e in the alkane name with –al • Common Add aldehyde to the prefixes form (1C), acet (2C), propion(3), and butry(4C) OOO    H-C-H CH3-C-H CH3CH2C-H methanal ethanal propanal (formaldehyde) (acetaldehyde) (propionaldehyde)

4. Methanal • common name: formaldehyde • 40% in water is formalin, a preservative

5. Aldehydes as Flavorings

6. Glucose is an aldehyde

7. Naming Ketones • In the IUPAC name, the -e in the alkane name is replaced with -one • In the common name, add the wordketone after naming the alkyl groups attached to the carbonyl group OO   CH3 -C-CH3 CH3-C-CH2-CH3 Propanone 2-Butanone (Dimethyl ketone) (Ethyl methyl ketone)

8. Propanone • Common name: acetone • nail-polish remover • miscible with water in all proportions

9. Ketones O O   Butter flavor CH3-C-C-CH3 butanedione O  Clove flavor CH3-C-CH2CH2CH2CH2CH3 2-heptanone

10. Fructose is a Ketone

11. Ketones as Hormones

12. Aldehydes and Ketones • Neither can form intermolecular hydrogen bonds, thus a much lower b.p. than corresponding alcohols

13. Learning Check Classify each as an aldehyde (1), ketone (2) or neither(3). O  A. CH3CH2CCH3 B. CH3-O-CH3 CH3 O  C. CH3-C-CH2CH D. CH3

14. Solution Classify each as an aldehyde (1), ketone (2) or neither(3). O  A. CH3CH2CCH3 2B. CH3-O-CH3 3 CH3 O  C. CH3-C-CH2CH 1 D. 2 CH3

15. Learning Check Name the following O  A. CH3CH2CCH3 B. CH3 O  C. CH3-C-CH2CH CH3

16. Solution O  A. CH3CH2CCH3 B. 2-butanone (ethyl methyl ketone) CH3 O  C. CH3-C-CH2CH cyclohexanone CH3 3,3-dimethylbutanal

17. Learning Check Draw the structural formulas for each: A. 3-Methylpentanal B. 2,3-Dichloropropanal C. 3-Methyl-2-butanone

18. Solution Draw the structural formulas for each: CH3 O  A. 3-Methylpentanal CH3CH2CHCH2CH Cl O  B. 2,3-Dichloropropanal Cl-CH2CHCH O  C. 3-Methyl-2-butanone CH3CHCCH3 CH3