Chapter 20
The carbonyl can be an electrophile, it can be attacked. It can occur under basic or acidic conditions.
Basic Conditions:
O 1. Nu O
H
2. H
2
O workup
Nu
Nu:
H OH
O :
Nu
Acidic Conditions:
H +
O : 1. H + , Nu: O
H
Nu
H
O
+
OH
Nu
Nu:
Hydride reductions. Basic conditions, H is the nucleophile
Ketones and aldehydes react w/ LiAlH
4
.

O 1. LiAlH
2. H
4
2
O workup
O
H
H
H:
-
H OH
O :
H
Esters and acid chlorides react w/ LiAlH
4
.
O
OMe
1. LiAlH
4
2. H
2
O workup
H:
-
O
H
H
H
H OH
O : O O :
OMe H
H
H
H
H:
-
There are many sources of hydride with various reactivities
Hydride
Donors
Aldehyde Ketone Ester Amide Carboxyllic acid/ acid salt
LiAlH
4
Alcohol
LiAlH(OtBu)
3
Alcohol
NaBH
4
NaBH
3
CN
Alcohol
Alcohol
Alcohol
Alcohol
Alcohol
N.R.
Alcohol
Alcohol
N.R.
N.R.
Amine
- (too slow) N.R.
N.R.
N.R.
Alcohol
N.R.
N.R.
DIBAL-H Alcohol Alcohol Aldehyde * Aldehyde* Alcohol
* Stoichiometry must be carefully controlled.
H
2,
Pd/C reacts preferentially with carbon-carbon double bonds.
Carbon Nucleophiles:
Both of the following create reagents that act like CH
3
-
.
EtBr + 2Li →EtLi + LiBr
EtBr + Mg → EtMgBr
Alkyne nucleophiles.
CH
3
C≡CH + NaNH
2
→ CH
3
CH
3
C≡CH + CH
3
Li → CH
3
C≡C: - Na + + NH
C≡C: -
Li
+
+ CH
4
3
↑
CH
3
C≡CH + CH
3
MgBr → CH
3
C≡CMgBr
+ CH
4
↑
?
?
?
Acid halide
Alcohol
Aldehyde

Ketones and aldehydes react w/ these carbon nucleophiles.
O 1. H
3
C C C MgBr
2. H
2
O workup
O
C
CH
3
CC:
-
H
C
CH
3
H OH
O :
Esters and acid chlorides react w/ these carbon nucleophiles.
O
OMe
1. CH
3
Li or CH
3
2. H
2
O workup
MgBr O H
CH
CH
3
3
H
3
C:
-
O : O O :
H
3
C
OMe
H
3
C:
-
H CH
3
CH
3
Grignards react with carbon dioxide to for carboxylic acids.
O
C
O
1. CH
3
MgBr
2. H
2
O workup
H
3
C
O H
O
CH
3
:
-
H OH
O :
H OH
H
3
C O
Cuprates are another source of carbon anions but they react differently then the carbon nucleophiles we have seen before. In enones they react at the 4 position and they can react with alyls halides including vinyl and aryl halides

Preparation
2MeLi + CuI → Me
2
CuLi
O
1. CH
3
MgBr
2. H
2
O
O
1. (CH
3
)
2
CuLi
2. H
2
O workup
H
3
C OH
O
1,2 addition
1, 4 addition
H
3
C
O
H
3
C
Cuprates can substitute alkyl groups for halogens (primary) which is no big deal but they can also do it with vinyl and aryl halides!!
Br
(CH
3
)
2
CuLi H
3
C
Br
(CH
3
)
2
CuLi H
3
C
Alkyl anions can react with epoxides.
O
1. CH
3
MgBr
2. H
2
O workup
OH
O
H
3
C

Br MgBr OH
OH
Chomium(VI) reagents oxidize alcohols to ketones. (p434)
OH
O
+ HCrO
3
-
O
O
H
O Cr OH
O
Primary alcohols and aldehydes are oxidized to carboxylic acids
O
OH
H
H
2
O
OH
H
2
CrO
4
H
OH
H
2
CrO
4
Silver(I) will oxidize aldehydes to carboxylic acids.
O
O
Ag
2
O
H
NH
4
OH
OH
Br
O
OH