Homework 5
Organic Chemistry MCAT Review
Summer 2012
Brent Iverson
1
1. For the following reactions, draw the predominant product or products. When a new chiral center is
created, mark it with an asterisk (*) and if a racemic mixture is produced, you must write "racemic" under
your structure. If an E,Z mixture is produced as the result of a dehydration step, write E,Z mixture, but
you only have to draw one isomer, not both. These directions are different than you may have seen
before, and are intended to make it easier for you. You should read them again so you know what we
want.
No dehydration here because no
acid/heat treatment
OH
O
*
O
E,Z Mixture
Racemic
H
H
*
O
E,Z Mixture
H
1.0 eq. NaOH
(No acid or heat)
1) 0.5 eq. LDA
2) H3O
/Δ
1) catalytic NaOH
2) H3O
O
/Δ
H
O
N
/H
N
H
Br
1)
2) H3O
O
O
O
O
1) Cl
*
Racemic
2) H3O
*
Racemic
2
2. For the following reactions, draw the predominant product or products. When a new chiral center is
created, mark it with an asterisk (*) and if a racemic mixture is produced, you must write "racemic" under
your structure. If an E,Z mixture is produced as the result of a dehydration step, write E,Z mixture, but
you only have to draw one isomer, not both. These directions are different than you may have seen
before, and are intended to make it easier for you. You should read them again so you know what we
want.
O
O
*
O
O
O
Racemic
O
O
*
O
1) 1.0 eq. LDA
Racemic
O
2)
O
3) H3O
1.0 eq. LDA
(Mild acid)
no heat
2) H 3O
O
O
1) 0.5 eq. NaOEt
(Mild acid)
no heat
O
1,4 addition
1.0 eq. NaOH
O
Br
HO
O
(Hot;
thermodynamic
control)
HBr
(Cold; kinetic control)
excess
H2CrO4
O
HO
HBr
OH
1,2 addition
O
cat. H2SO4
excess
O
O
Br
Br
O
Racemic
OH
3
3. Fill in the boxes with the predominant product formed under the reaction conditions. If a new chiral
center is formed in a racemic mixture, put an asterisk (*) next to it and write "racemic". If there is an aldol
reaction on this page DO NOT DEHYDRATE IT!!!
O
H
*
*
OH
OH
racemic
1) NaBH4
2) H2O
O
cat. NaOH
OH
O
H2CrO4
OH
H
*
MgBr
1)
2) mild H3O
H
racemic
OH
HO
Ph3P
CHCH3
cat. H
Z product
O
O
H
H
4
4. Fill in the boxes with the predominant product formed under the reaction conditions. If a new
chiral center is formed in a racemic mixture, put an asterisk (*) next to it and write "racemic".
O
O
0.5 eq. NaOEt
Mild H3O
O
O
No heat
O
O
O
O
Br
Racemic
*
O
O
O
+ CO2
1) Strong H3O
2) Heat (Δ)
HO
O
1)
MgBr
2) H3O
*
OH
Racemic
5
5. Fill in the box with the product or products that are missing from the following chemical reaction
equations. When a racemic mixture is formed, you must write "racemic" under both structures EVEN
THOUGH YOU DREW BOTH STRUCTURES.
H3O
C
OH
heat
N
O
SOCl2
O
O
O
O
O
Cl
O
1)
2
CuLi
2 eq.
2) H2O
NH
N
O
O
1)
2) HCl / H2O
MgBr
1) LiAlH4
2) H2O
OH
Racemic
OH
N
6
6. Fill in the box with the product or products that are missing from the following chemical reaction
equations. When a racemic mixture is formed, you must write "racemic" under both structures EVEN
THOUGH YOU DREW BOTH STRUCTURES.
Note: in principle, this could react on either side of
the carbonyl, but due to accessibility, i.e. the methyl
group is more accessible, reaction is always
observed at the methyl group in these reactions.
Haloform reaction
CH3
CH3Cu + LiCl
OH
1) NaOH / excessBr2
2) H3O
O
O
1. (CH3)2CuLi
2. H2O
CH2-P(Ph)3
+ CHBr3
SOCl2
Cl
CH3
O
CH2
OH
H2 / Pd
(1st semester)
O
O
1) LiAlH4
2) H2O
NH3
heat
OH
OH
NH2
OH
O
7
7. For the following reactions, draw the predominant product or products. When a new chiral center is
created, mark it with an asterisk (*) and if a racemic mixture is produced, you must write "racemic" under
your structure. If an E,Z mixture is produced as the result of a dehydration step, write "E,Z mixture", but
you only have to draw one isomer, not both. These directions are different than you may have seen
before, and are intended to make it easier for you. You should read them again so you know what we
want.
O
O
O
O
1)
1) 1.0 eq.NaOEt
2) H3O
(mild acid, no heat)
O
exc
ess
L iA
2)
H
lH
2O
4
HO
OH
2
OH
O
*
O
(racemic)
O
CH3
O
1) 1.0 eq.NaOEt
O
2)
O
*
4
lH
A
Li
ss O
ce
ex ) H 2
2
1)
3) H3O
(stronger acid, with
heat)
O
(racemic)
OH
*
CH3
*
*
OH
(racemic)
Hardest problem: How
many different
stereoisomers are
created in this reaction?
6
(There are two meso compounds)
8
8. Fill in the boxes with the predominant product formed under the reaction conditions. If a new chiral
center is formed in a racemic mixture, put an asterisk (*) next to it and write "racemic". If ortho/para
products are created, you must draw both.
CO2H
Br
H2CrO4
Br 2
hν
Cl
AlCl3
Br
2
Br
3
Br
Fe
*
HNO3
racemic
NO2
H2SO4
OH
H2O
H2
Ni
H3PO2
NH2
O
N2
Cl
NaNO 2
HCl
O
N
C
K CN
u
C
O
KI
I
CN
9
9. For the following reactions, fill in theboxes with the predominant product or products. When
ortho/para products are both produced, you must draw both. When a new chiral center is produced, put
an asterisk (*) next to it. If a racemic mixture is produced, you must write racemic.
HNO3
NO2
NH2
H2
H2SO4
Ni
Br2
FeBr3
NaNO2 / HCl
Br
CN
N2
KCN
CuCN
Mg ° / ether
(yes, this works)
MgBr
1) CO2
H3O
(strong
with heat)
HCl
CuCl
H2O
OH
CO2H
Cl
2) H3O
(mild)
O
1) 1.0 Eq. LDA
Cl
2) CH3Br
O
OCH3
O
NO2
OCH3
OCH3
HNO3
H2SO4
O2N
10
10. For the following reactions, fill in theboxes with the predominant product or products. When
ortho/para products are both produced, you must draw both. When a new chiral center is produced, put
an asterisk (*) next to it. If a racemic mixture is produced, you must write racemic.
CH3
CH3
HNO3 / H2SO4
CH3
NO2 O2N
CH3
SO3H
CH2Br
Br2 / hν
HNO3 / H2SO4
O2N
O
SO3H
O
Br2
Br
FeBr3
OH
CO2H
*
H2CrO4
racemic
CO2H
H2CrO4
11
11. For the following reactions, fill in theboxes with the predominant product or products. When
ortho/para products are both produced, you must draw both. When a new chiral center is produced, put
an asterisk (*) next to it. If a racemic mixture is produced, you must write racemic.
NO2
NO2
Br2 / FeBr3
NO2
CH3
CH3
NO2
Br
CH3
Br
Br
Br2 / FeBr3
NO2
NO2
Br
OH
OH
OH
Br
O
O
Br2 / FeBr3
O
Assume
only one
Br atom
adds
O
O
O
Br
Cl
Cl
Br
Cl
Br2 / FeBr3
Br
OCH3
OCH3
OCH3
12