(1) Predict the major product from each reaction. If you expect no reaction, indicate.
O
Ph3P=CHPh
H
(a)
H
Ac2O
(b)
DMAP
pyridine
N
H
N
O
O
(c)
O
OH
OH
O2N
O
O
PPh3, DEAD
O
(d)
OEt
CH3CH2OH
H
OCH3
OEt
OCH3
TsOH(cat.)
O
(e)
NO2
O
O
HCN
CN
O
OH
O
(f)
TsOH
N
NH
CH3
CH3
O
O
O
N
(g)
N
H
HOAc (cat.)
(h)
CO2H
O
NH2
DCC
O
N
H
O
(2) Which of these two compounds is more acidic and why?
O
O2N
O
OH
H3CO
OH
The nitro group is electron withdrawing and helps stabilize the conjugate base (carboxylate)
O
O2N
O
(3) Fill in the compounds in the following roadmap (only show the major product for each step)
O
1) O3 then Me2S
H
2) HOCH2CH2OH,
(only one equivalent)
O
O
TsOH, MgSO4
O
O
MgBr
3)
O
Ph
4) Ac2O, pyridine
OH
O
then
work-up
Ph
O
DMAP
O
O
O
O
5) HCl, H2O
O
Ph
6) NH2OH
O
H
O
HOAc (cat.)
Ph
O
H
N OH
(4) The following reaction is known as a Yamaguchi coupling and is very selective for the formation of
the compounds below (no other products are formed). Can you explain this selectivity? (hint: a species
known as a mixed anhydride is involved)
Cl
O
O
Cl
1)
Cl
OH
O
+ Et3N (a base)
Cl
O
2)
+ Et3N (a base)
O
O
O
O
(only isomer)
HO
this carbonyl is deactivated
electronically and sterically
by the aryl ring and therefore
only the other carbonyl
reacts with the nucleophile
Cl
O
Cl
Cl
(mixed anhydride)
(5) Using benzene and ethanol as your only carbon source, synthesize the following molecule. You
may use any inorganic reagents.
O
O
OCH2CH3
N
H
O
O
KMnO4
O
OH
SOCl2
OEt
+
Cl
H2N
H2, Pd
CH3
CH3Cl
O
O
AlCl3
CH3
HNO3
H2SO4
OH
KMnO4
O2N
OEt
EtOH, HCl
O2N
O2N
(6) Give a detailed mechanism for the following reaction
O
O
OCH3
HN
O
O
N
H
OCH3
OCH3
NH2
O
HN
H2O
NH2
O
N
H
N
H
O
O
OCH3
HN
O
N
H
NH2
* several other reasonable variations
N
H
N
H
O
HN
O
H
H
HN
O
H
OCH3 -MeOH
HN
O
N
H
HCl
N H
H
N
H
-MeOH
OCH3 PT HN
O
N
H
N
H
OCH3
H
O
(7) In the last question, why isn't the imine below the product ?
HN
O
N
N
H
The enamine isomer has an aromatic ring and hence it is more stable
(8) Fill in the compounds in the following roadmap (only show the major product for each step)
OH
O
EtO P
1) EtO
O
1) PCC
H
2) NaOH, Me2SO4
HO
O
CH3
NaOH
H3CO
O
HO
H
1) (H2C=CH)2CuLi
H3CO
2) CH3MgBr
H3CO
HO
1) O3
OH
2) Jones
H3CO
O
1) DCC
O
H3CO
(9) List the reagents (in order) needed to accomplish the following transformations
O
1) NaBH4
CH2NH2
2) PBr3
O
3) NaCN
4) LiAlH4 (LAH)
O
O