Aldehydes and Ketones In an aldehyde, a carbon group and an H atom is attached to a carbonyl group Ocarbonyl group  CH 3 - C - H carbonyl group always joined to at least one hydrogen (meaning it is always on the end!)

Aldehydes and Ketones In a ketone, two carbon groups are attached to a carbonyl group O carbonyl group  CH 3 - C - CH 3 carbon of the carbonyl group is joined to two other carbons (meaning it is never on the end)

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) O O O    H-C-H CH 3 -C-HCH 3 CH 2 C-H methanal ethanal propanal (formaldehyde) (acetaldehyde) (propionaldehyde)

l common name: formaldehyde l 40% in water is formalin, a preservative Methanal

Aldehydes as Flavorings

Glucose is an aldehyde

Naming Ketones In the IUPAC name, the -e in the alkane name is replaced with -one In the common name, add the word ketone after naming the alkyl groups attached to the carbonyl group O  CH 3 -C-CH 3 CH 3 -C-CH 2 -CH 3 Propanone 2-Butanone (Dimethyl ketone) (Ethyl methyl ketone)

Propanone l Common name: acetone l nail-polish remover l miscible with water in all proportions

Ketones O O  Butter flavorCH 3 -C-C-CH 3 butanedione O  Clove flavorCH 3 -C-CH 2 CH 2 CH 2 CH 2 CH 3 2-heptanone

Fructose is a Ketone

Ketones as Hormones

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

Learning Check Classify each as an aldehyde (1), ketone (2) or neither(3). O  A. CH 3 CH 2 CCH 3 B. CH 3 -O-CH 3 CH 3 O  C. CH 3 -C-CH 2 CHD. CH 3

Solution Classify each as an aldehyde (1), ketone (2) or neither(3). O  A. CH 3 CH 2 CCH 3 2 B. CH 3 -O-CH 3 3 CH 3 O  C. CH 3 -C-CH 2 CH 1 D. 2 CH 3

Learning Check Name the following O  A. CH 3 CH 2 CCH 3 B. CH 3 O  C. CH 3 -C-CH 2 CH CH 3

Solution O  A. CH 3 CH 2 CCH 3 B. 2-butanone (ethyl methyl ketone) CH 3 O  C. CH 3 -C-CH 2 CH cyclohexanone CH 3 3,3-dimethylbutanal

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

Solution Draw the structural formulas for each: CH 3 O  A. 3-MethylpentanalCH 3 CH 2 CHCH 2 CH Cl O  B. 2,3-Dichloropropanal Cl-CH 2 CHCH O  C. 3-Methyl-2-butanoneCH 3 CHCCH 3 CH 3