Aldehydes and Ketones

Drill Draw & name 5 isomers of: C3H5OF

Organic compounds with carbonyl groups on the end carbon Aldehydes Organic compounds with carbonyl groups on the end carbon

Aldehydes O R-C H

Organic compounds with carbonyl groups within carbon chains Ketones Organic compounds with carbonyl groups within carbon chains

Ketones O R-C-R

Common Aldehydes

Formaldehyde O H-C H Methanal

Acetaldehyde O CH3-C H Ethanal

Propionaldehyde O CH3-CH2-C H Propanal

Butyraldehyde O CH3CH2CH2C H Butanal

Benzaldehyde O C H Almond Extract

Cinnamaldehyde O

all-trans-retinal H C=O

all-trans-retinol

4-hydroxy-3-methoxy benzaldehyde H3C-O O C HO H Vanillin

Draw: acetaldehyde & benzaldehyde

Common Ketones

Acetone O CH3-C CH3 Propanone

Methyl ethyl ketone O CH3CH2C CH3 Butanone

Cyclohexanone O

Benzophenone O C Diphenylmethanone

Muscone O

General Properties

Polarity Alcohols > aldehydes Aldehydes > ketones

Solubility in Water Alcohols > aldehydes Aldehydes > ketones

Boiling Points Alcohols > aldehydes Aldehydes > ketones

Melting Points Alcohols > aldehydes Aldehydes > ketones

Oxidation State Alcohols > hydrocarbons Aldehydes > alcohols Acids > aldehydes

Show all the oxidation steps in converting butane to 3-butenoic acid

Energy State Alcohols < hydrocarbons Aldehydes < alcohols Acids < aldehydes

Chm PE Gradient Methane: CH4 Methanol: CH3OH Methanal CH2O Methanoic A: HCOOH

Chm PE Gradient Reduced Compounds > Less reduced compounds > Oxidized compounds

Determine MP order CH3-CH3 CH3-CH2OH CH3-CHO CH3-COOH

Drill: Draw & name 5 isomers of: C3H9NO

Making Aldehydes & Ketones

Making Aldehydes Oxidation of primary alcohols

Making Aldehydes To oxidize alcohols, Hs must be removed from the OH & the adjacent carbon

Making Aldehydes OH R-C-H H ox

Making Aldehydes OH R-C-H H ox

Making Aldehydes OH O R-C-H R-C H H ox

Common Oxidizing Agents Cr2O7-2 MnO4-1

Examples: K2Cr2O7 KMnO4

Oxidation of secondary alcohols Making Ketones Oxidation of secondary alcohols

Making Ketones OH R-C-R ox H

Making Ketones OH O R-C-R R-C R ox H

t-Alcohol Ox OH R-C-R R ox

t-Alcohol Ox OH R-C-R NR ox R

Name reactants & predict & name products K2Cr2O7 H2SO4 H3C-OH

Formaldehyde H C=O Methanal

Name reactants & predict & name products K2Cr2O7 H2SO4 H2C-OH H3C

Acetaldehyde H C=O H3C Ethanal

Name reactants & predict & name products OH H3C-CH-CH3 K2Cr2O7 H2SO4

Acetone H3C C=O Propanone

Name reactants & predict & name products OH K2Cr2O7 H2SO4

Cyclohexanone O

Name reactants & predict & name products CH2OH K2Cr2O7 H2SO4

Aldehyde Detection

Detecting Aldehydes Tollen’s Test Benedict’s & Fehling’s Test Both distinguish aldehydes from ketones

Tollen’s Reagent AgNO3 Ag+ + NO3- Ag+ + 2 NH3 [Ag(NH3)2]+ 100 %

Tollen’s Test R-C-H + 2[Ag(NH3)2]+ + 2OH- O NH4+R-CO- + 2Ag(s)+3NH3 + H2O

Benedict’s Reagent CuSO4 Cu+2 + SO4-2 NaOH Na+ + OH- Fehling’s Reagent 100 % 100 % Fehling’s Reagent

Benedict’s Test O R-C-H + 2 Cu+2 + 5 OH- R-C-O- + Cu2O(s) + 3H2O

Yield positive results in both tests a-Hydroxy Ketones HO O R-C-C H R Yield positive results in both tests

Carbonyl Addition Reactions

Carbonyl Addition Rxns with water C + H-OH C Hydrate HO OH

Carbonyl Addition Rxns Chloral or trichloroacetaldehyde O C + H-OH H Cl3C H CCl3 C Chloral Hydrate HO OH

Carbonyl Addition Rxns Methanal O C + H-OH H H

Carbonyl Addition Rxns C + H-OH H H H H C Methanediol HO OH

Carbonyl Addition Rxns with alcohols C + R-OH C RO OH

Example O C + OH H3C H

HO O C H3C H

Draw & name 4 isomers C5H10O that are either aldehydes or ketones: Drill: Draw & name 4 isomers C5H10O that are either aldehydes or ketones:

Hemiketal Formation O C + R3-OH R1 R2 R1 R2 C Hemiketal R3-O OH

Name reactants & draw products C + CH3-OH H3C CH3

O C + CH3-OH H3C CH3 CH3 CH3 C Hemiketal H3C-O OH

Hemiacetal Formation O C + R3-OH R1 H R1 H C Hemiacetal R3-O OH

Hemiacetal Formation O C + R3-OH H3C H CH3 H C Hemiacetal R3-O OH

Hemiacetal Formation O C + R3-OH H3C H CH3 H C Hemiacetal R3-O OH

Draw the reactants & products when water is added to 2-butanone

Draw the reactants & products when methanol is added to acetone

Full Acetals & Ketals The second addition of an alcohol to either hemi- acetals or ketals will produce full each

Uses of Aldehydes & Ketones

6) formaldehyde + 1-butanol 1) 1-propanol + KMnO4 2) 2-propanol + K2Cr2O4 3) 2-methyl-2-propanol + K2Cr2O4 4) cyclohexanone + water 5) benzaldehyde + water 6) formaldehyde + 1-butanol 7) acetone + phenol 8) 5-hydroxypentanaldehyde (addition)

6) propanaldehyde + methanol 1) ethanol + KMnO4 2) 2-pentanol + K2Cr2O7 3) t-butanol+ K2Cr2O7 4) acetone + water 5) formaldehyde + water 6) propanaldehyde + methanol 7) 2-butanone + phenol 8) 4-hydroxybutanaldehyde (addition)

Name the following: O OH H

Review

Name the following: OH O H

Draw the following: 3-ethyl-2-phenoxy-1-sulfhydryl-octa-4,5-dione

Oxidation of each with KMnO4 or K2Cr2O7: 1-butanol 2-butanol 2-methyl-2-propanol

Carbonyl Addition Rxns: 2-butanone + water Propanaldehyde + water Acetone + methanol Acetaldehyde + ethanol

Draw the reactants & products when 5-hydroxypentanal reacts with itself

Draw & name 5 isomers of C4H8O containing carbonyls