aldehydes and ketones. drill draw & name 5 isomers of: c 3 h 5 of
TRANSCRIPT
Aldehydes and Ketones
DrillDraw & name 5 isomers of:
C3H5OF
Aldehydes•Organic compounds with carbonyl groups
on the end carbon
Aldehydes O
R-C
H
Ketones•Organic compounds with carbonyl groups within carbon chains
Ketones
O
R-C-R
Common Aldehydes
Formaldehyde O
H-C
HMethanal
Acetaldehyde O
CH3-C
HEthanal
Propionaldehyde O
CH3-CH2-C
HPropanal
Butyraldehyde O
CH3CH2CH2C
HButanal
Benzaldehyde O
C
HAlmond Extract
Cinnamaldehyde
O
all-trans-retinal
C=OH
all-trans-retinol
4-hydroxy-3-methoxy benzaldehyde
Vanillin
CO
HHO
H3C-O
Draw: acetaldehyde
& benzaldehyde
Common Ketones
Acetone O
CH3-C
CH3Propanone
Methyl ethyl ketone O
CH3CH2C
CH3Butanone
Cyclohexanone
O
Benzophenone
CO
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
•Oxidation of primary alcohols
Making Aldehydes
•To oxidize alcohols, Hs must be removed from the OH & the
adjacent carbon
Making Aldehydes
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
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
H3C-OHK2Cr2O7
H2SO4
Formaldehyde H
C=O
H Methanal
Name reactants & predict & name products
H2C-OH
H3C
K2Cr2O7
H2SO4
Acetaldehyde H
C=O
H3C Ethanal
Name reactants & predict & name products
OH
H3C-CH-CH3K2Cr2O7
H2SO4
Acetone H3C
C=O
H3C Propanone
Name reactants & predict & name products
K2Cr2O7
H2SO4
OH
Cyclohexanone
O
Name reactants & predict & name products
K2Cr2O7
H2SO4
CH2OH
Benzaldehyde
CHO
Aldehyde Detection Reactions
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 O
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-
100 %
100 %
Fehling’s Reagent
Benedict’s Test O
R-C-H + 2 Cu+2 + 5 OH-
O
R-C-O- + Cu2O(s) + 3H2O
-Hydroxy Ketones HO O
R-C-C
H RYield positive results in both tests
Drill: Draw-hydroxy-
propanaldehyde
Carbonyl Addition Reactions
Carbonyl Addition Rxns with water O
C + H-OH
CHO OHHydrate
Carbonyl Addition Rxns
O C + H-OH
CHO OH
ChloralHydrate
HCl3C
Chloral ortrichloroacetaldehyde
H CCl3
Carbonyl Addition Rxns
O C + H-OH
HH
Methanal
Carbonyl Addition Rxns
O C + H-OH
CHO OH
Methanediol
HH H H
Carbonyl Addition Rxns with alcohols O
C + R-OH
CRO OH
Example O
C + OHH3C H
CH3C H
HO O
Drill:•Draw & name 4
isomers C5H10O that are either aldehydes
or ketones:
Hemiketal Formation
O
C + R3-OH
CR3-O OH
R1 R2 R1 R2
Hemiketal
Name reactants & draw products O
C + CH3-OH
H3C CH3
O
C + CH3-OH
CH3C-O OH
H3C CH3CH3 CH3
Hemiketal
Hemiacetal Formation
O
C + R3-OH
CR3-O OH
R1 H R1 H
Hemiacetal
Hemiacetal Formation
O
C + R3-OH
CR3-O OH
H3C H CH3 H
Hemiacetal
Hemiacetal Formation
O
C + R3-OH
CR3-O OH
H3C H CH3 H
Hemiacetal
Draw the reactants & products when water
is added to2-butanone
Draw the reactants & products when
methanol is added toacetone
Full Acetals & Ketals
•The second addition of an alcohol to either hemi- acetals or ketals will produce full each
Uses of Aldehydes &
Ketones
1) 1-propanol + KMnO4
2) 2-propanol + K2Cr2O4
3) 2-methyl-2-propanol + K2Cr2O4
4) cyclohexanone + water
5) benzaldehyde + water6) formaldehyde + 1-butanol7) acetone + phenol
8) 5-hydroxypentanaldehyde (addition)
1) ethanol + KMnO4
2) 2-pentanol + K2Cr2O7
3) t-butanol+ K2Cr2O7
4) acetone + water
5) formaldehyde + water6) propanaldehyde + methanol7) 2-butanone + phenol
8) 4-hydroxybutanaldehyde (addition)
Name the following:
OH
H
O
Review
Name the following:
O
H
OH
Draw the following:•3-ethyl-6-methyl-
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 3 isomers of C4H8O
containing carbonyls
Draw & name 10 isomers of
C4H8O