Chapter 15 and GHW#5 Questions Aldehydes and Ketones

Bonding Characteristics of Aldehydes Ketones Both aldehydes and ketones contain a carbonyl functional group. A carbonyl group is an carbon atom double-bonded to an oxygen atom. The structural representation for a carbonyl group is Carbon-oxygen (C=O) and carbon-carbon (C=C) double bonds differ in a major way. A carbon oxygen double bond is more polar

Physical Properties of Aldehydes and ketones BP and MP are lower than alcohols , higher than hydrocarbons and ether with comparable carbon numbers

1. Assign the type of organic compound with following general condensed (structural formula.

Common Names of Aldehyde and Ketones Aldehydes: Fomaldehyde: HCHO Acetaldehyde: CH3CHO Propionaldehyde: CH3CH2CHO Butyraldehyde: CH3CH2CH2CHO Valeraldehyde: CH3CH2CH2CH2CHO Ketones: Acetone: CH3COCH3 Methyl ethyl ketone CH3CH2COCH3 Butyl propyl ketone CH3CH2CH2CH2COCH2CH2CH3

IUPAC Nomenclature of Aldehyde and Ketones The IUPAC system deals with functional groups two different ways. Modification of the hydrocarbon name to indicate the presence of a functional group. aldehyde, -CHO use -al ending. Ketones -RCOR’ use -one ending.

2. Names (common/IUPAC)of following aldehydes and ketones. a) ____________ b) _______________ c) __________________ d) ____________ e) _______________ f) __________________ g) ____________ h) __________________

3. Draw the condensed formula of following aldehydes and ketones: acetaldehyde/ ethanal b) ethyl methyl ketone   c) 3-methyl-2- pentanone d) isopropyl methyl e) 2-methylbutanal f) 5-methyl-3- hexanone g) benzophenone h) acetophenone

4. Identify each of the following compounds as a hemiacetal, hemiketal, acetal, or ketal: a) ____________ b) _______________ c) __________________ d) ____________ e) _______________ f) __________________

Chemical Reactions of Aldehydes and Ketone 1) Combustion: Alkenes are very flammable and the combustion products are carbon dioxide and water. 2) Addition Reactions: Atoms or group of atoms are added to each a carbon oxygen double bond. Two different reactants are involved. a) hemi-acetal or hemi-ketal formation: Addition of Alcohols: -OR group of the R-OH is added to the C atom and H of the ROH is added to O atom. b) Aacetal or ketal formation : Another or second ROH is reacted in a substitution reaction to replace the H atom of the -OH group of the hemi-acetal or hemi-ketal and water molecule is produced. O: both reactants (H-X (X= Cl, OH)) and the alkene need to be asymmetric 3) Oxidation Reactions: only aldehydes are oxidized to carboxylic acids. 4) Reduction Reactions: both aldehydes and ketones are reduced to alcohols by taking H from the reducing agents.

5) Which alcohol would you oxidize to produce each of the following compounds? b) c) d)

6) Preparation of adehydes and ketones a) Control oxidation of 1ry alcohol b) Complete oxidation of 1ry alcohol

6) Preparation of adehydes and ketones c) Oxidation of 2ry alcohol d) Oxidation of 3ry alcohol No Reaction

7) Complete the following reductions of aldehyde and ketones and identify the type of alcohols (1ry, 2ry and 3ry) produced. d)

8) Complete the following formation reactions hemiacetal, hemiketal, acetal, or ketal:

9) Complete reactions of following aldehydes and ketones Tollen’s Reagent: Silver mirror test: Benedict's test:

9) Complete reactions of following aldehydes and ketones c) Oxidation of aldehyde d) Cyclic hemi-acetal formation