4. IUPAC Nomenclature of Ketones
• Ch
Choose th l
the longest continuous carbon chain th t
t ti b h i that
contains the carbonyl carbon
• Number from the end of the chain closest to the
carbonyl carbon
• Ketone ending is -one
Do the ketones section of Organic Nomenclature
g
program!
5. EXAMPLES
O
C CH 2
CH 3 CH 2 CH 3
2-Pentanone O
CH3 C CH2
CH2 CH CH3
CH2
CH3
4-Ethyl-3-hexanone
7. KETONES
Common,
Common or Trivial Names
Trivial,
• Name each group attached to the carbonyl
group as an alkyl group
• Combine into a name, according to the pattern:
alkyl alkyl’ k t
lk l lk l’ ketone
NOTE:
NOTE This is not all one word!
8. Example of Common Names
O
C CH 2
CH 3 CH 2 CH 3
Methyl propyl ketone O
CH3 C CH3
CH2 CH2
Diethyl ketone
9. SPECIAL CASES
O O
C C
CH3 CH3
diphenyl ketone
dimethyl k t
di th l ketone
benzophenone
acetone
A common laboratory O
solvent and cleaning
agent
g C CH3
methyl phenyl ketone
KNOW
THESE
acetophenone
10. IUPAC Nomenclature of Aldehydes
• Choose the longest continuous carbon chain that
contains th carbonyl carbon
t i the b l b
• Number from the end of the chain closest to the
carbonyl carbon (carbon #1!)
• Aldehyde ending is -al
Do the aldehydes section of Organic Nomenclature
program.
11. EXAMPLES
aldehyde group is
CH2 CH2 O always carbon 1
H3C CH2 C
H
pentanal
Cl
CH3 3 CH 1
O
4 CH 2 C
CH3 H
2 chloro 3 methylbutanal
2-chloro-3-methylbutanal
12. Common Names of the Aldehydes
O O O
C C C
H H CH3 H H3C CH2 H
Formaldehyde Acetaldehyde Propionaldehyde
1 2 3
O O
C C
H3C CH2 C H H3C CH2 CH2 C H
Butyraldehyde Valeraldehyde
4 5
O
C
H3C CH2 CH2 CH2 CH2 H RECOGNIZE
Caproaldehyde THESE
6
13. SPECIAL CASES
O
C
H H O
formaldehyde C H
O
benzaldehyde
C
H CH3
KNOW
THESE
acetaldehyde
14. Forming Common Names of Aldehydes
USE OF GREEK LETTERS O
C C C C C C C H
ω ……. ε δ γ β α −−
ω is always the end of the chain, no matter how long
CHO CHO
Cl Cl
α-chlorocaproaldehyde
chlorocaproaldehyde ω-chlorocaproaldehyde
chlorocaproaldehyde
( α-chlorohexanal ) ( ω-chlorohexanal )
16. GENERALIZED CHEMISTRY
THE CARBONYL GROUP
nucleophilic
at oxygen
t
electrophiles H+ or E+
add here
.. δ- .. -
O: :O :
δ+
C C
+
nucleophiles
attack here
Nu:
electrophilic
at carbon
18. Nucleophilic Addition to Carbonyl
Basic or Neutral Solution
.. _
.. :O:
O: an
+
-:Nu slow
C
alkoxide
C ion
Nu
.. _ ..
:O: :O H
fast
C + H2O C
Nu or on adding acid Nu
Good nucleophiles
and strong b
d t bases BASIC SOLUTION
(usually charged)
19. Nucleophilic Addition to Carbonyl
Acid Catalyzed
+ more reactive to
.. :O H
O: fast addition than the un-
+
+ H C protonated precursor
C
..
.. + :O H
O H slow
+ C
C :Nu
Nu
(+)
Acid catalysis speeds the rate of
addition of ACIDIC SOLUTION
weak nucleophiles and
k l hil d stronger acid
weak bases (usually uncharged). pH 5-6 protonates the
nucleophile
21. Addition of Cyanide
y :C N:
Buffered to pH 6-8 .. _
:O : :O :
_
R C R + CN R C R
CN
.. _ ..
:O : :O H
R C R + H2O R C R
CN CN
a cyanohydrin
In acid solution there would be little CN-,
A cyanohydrin
and HCN (g) would be a problem (poison).
22. CYANIDE ION BONDS TO HEMOGLOBIN
..
CYANIDE IS
N Cyanide bonds
IS A POISON C (irreversibly) to the
.. site (Fe II) where
CH3 oxygen usually bonds.
H3C
N N You di f
Y die of
Fe suffocation -
N N lack of oxygen.
H3C CH3
CH2CH2COOH
CH2CH2COOH
HCN is a gas that you can easily breathe into your lungs.
24. Synthesis of Alcohols
Addition of Organometallic Reagents
.. _ +
:O : :O: M
ether
R M + R C R
C
(R-MgBr) R R
R
(R-Li)
:R - H2O workup
k
+ step
H
These reagents cannot
..
exist in acid solution :O H
R C R + M (OH)x
alcohol
l h l
R
25. Summary of Reactions of
Organometallics with
Carbonyl Compounds
All review
• Organometallics with ketones yield to
t you
tertiary alcohols
• Organometallics with aldehydes yield
secondary alcohols
• Organometallics with formaldehyde yield
primary alcohols.
• Organometallics with carbon dioxide yield
carboxylic acids.
etc.
27. Addition of Water
O O H
+
H
C + H2O R C R'
R R'
O H
aldehyde or ketone
favored a hydrate
hydrates are unstable
most hydrates revert to an aldehyde and cannot be isolated
or ketone as soon as they form in most cases
O H
O
R C R' + H2O
C
R R'
O H
28. ACID CATALYSIS
RECALL
H
+
O H
.. H .. ..
+
:O :O H :O H
+
Acid catalysis enhances the reactivity
of the carbonyl group - nucleophilic :Nu
N
addition proceeds more easily. weak nucleophiles
can react
Water is a weak nucleophile.
29. WATER ADDS TO THE CARBONYL GROUP OF
ALDEHYDES AND KETONES TO FORM HYDRATES
H catalyzed by a
+ trace of acid
O H
.. H .. .. ..
+ H H H
:O :O :O :O
C C
O+ :O a hydrate
.. H .. H .. H
O H
.. .. H
H O H
H
.. +
O H
H ..
for most compounds the equilibrium MICROREVERSIBILITY:
favors the starting materials
g In a reaction where all steps are
p
and you cannot isolate the hydrate reversible, the steps in the reverse
reaction are the same as those in
the forward reaction, reversed!
30. ISOTOPE EXCHANGE REVEALS THE PRESENCE
OF THE HYDRATE
O O18 an excess of H2O18
f
18 H+ shifts the equilibrium
+ H2O
R R R R to the right
excess
O H
+H2O18 -H2O
R C R
18 O
H exchange shows the
presence of a symmetric
intermediate
31. SOME STABLE HYDRATES
these also indicate that hydrates are possible
y p
δ−
Cl O Cl OH
Cl C Cl C OH
δ− δ+Cl H
Cl H
chloral chloral hydrate
δ−
120o expected
60o required OH
109o expected
O 60o required
sp2 sp3 OH
cyclopropanone
l cyclopropanone
l
hydrate
32. SOME ADDITIONAL STABLE HYDRATES
O O O OH
H C C H C C OH
glyoxal H
H
O O O OH
Ph C C Ph C C OH
H
H
phenylglyoxal
34. ACID CATALYSIS
RECALL
H
+
O H
.. H .. ..
+
:O :O H :O H
+
Acid catalysis enhances the reactivity
of the carbonyl group - nucleophilic :Nu
N
addition proceeds more easily. weak nucleophiles
can react
Alcohols are weak nucleophiles.
35. Addition of Alcohols
TWO MOLES OF ALCOHOL WILL ADD
addition of one mole
O O H
H+
hemiketal
R C R' + ROH R C R'
O R
addition of second mole
O H O R
H+
R C R' + ROH R C R' + H O
O R O R H
an aketal
The equilibria normally favor the aldehyde or ketone starting
material, but we will show how they can be made.
36. ACETALS AND HEMIACETALS
R R OH ROH R OR
ROH
C O C C
OR OR
H aldehyde H H
hemiacetal acetal
R R OH ROH R OR
ROH
C O C C
OR OR
R ketone R R
(hemiketal)*
(h ik t l)* (ketal)*
(k t l)*
*older term *older term
37. ..
R OH + H 2S O4 R O H Like a
+ hydronium
y
H ion
R
H O
+
.. .. H + ..
:O :O H :O H
R C R R C R R C R
.. O+
O H .. R
H .. R ..
ACID CATALYZED :
FORMATION OF A
first R O
addition H
HEMIACETAL
.. H
Normally the starting :O H
material is favored -
but a second molecule R C R + R O+
of alcohol can react .. H
if in excess (next slide) : ..
O
hemiacetal R
38. FORMATION OF THE ACETAL ( from the hemiacetal )
remove
R
H O
+ H ..
.. H O H
H
.. second
.. H .. : ..
O
addition
:O H + O H R
R C R R C R R C R
R C R +
:O
.. :O
..
SN1 :O + :O
R R R R
hemiacetal
Resonance
stabilized
.. .. .. carbocation
H
:O R R O: O R
+ H H +
R O
: R C R R C R
H :O :O
.. R .. R
acetal
39. STABILITY OF ACETALS AND HEMIACETALS
Most hemiacetals are not stable, except for those of sugars
(see later)
later).
Acetals are not stable in aqueous acid, but they are stable to
aqueous base
base.
OR H2SO4 ROH
AQUEOUS
ACID
C C O +
H2O
OR
ROH
AQUEOUS OR NaOH
BASE C no reaction
OR H2O
40. ADDITION OF WATER AND ALCOHOLS
WATER O H2O HO OH
C hydrate
y
ALCOHOLS
O R-O-H
ROH R-O-H
ROH
HO OR RO OR
C
H2O
hemiacetal acetal
O acetals are
RO OR H+
+2 ROH stable to base
H2O
but not to
H2O aqueous acid
no reaction
NaOH
42. OKSIDASI ALDEHID DAN KETON
• Keton tidak mudah dioksidasi
• Aldehid sangat mudah dioksidasi menjadi
dioksidasi,
asam karboksilat
Zat pengoksidasi : KMnO4, H, H2O
44. Reaksi Reduksi
• Reduksi aldehid menghasilkan alkohol primer
• Reduksi keton menghasilkan alkohol sekunder
• Zat pereduksi:
H2, katalis
H2 k li
Zn/Hg, HCl
47. Ramalkan produk hemiasetal atau
hemiasetal siklik dari:
1. 5 hidroksi 2 heksanon
1 5-hidroksi-2-heksanon dengan air
2. 1,3,4,5,6-pentahidroksi-2-heksanon
dengan air
3. propanal dengan metanol
4. Aseton dengan 1,2,3-propanatriol
