Orgo PS1
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O Br Me Me O E O E Propose syntheses of the following compounds starting from benzene and any other reagents you might need. Electrophilic aromatic substitution is possible with aromatic systems other than benzene. For example, furan can undergo substitution to give the following products (E(+) = Electrophile): 2. 1. E(+) + Major Product Minor Product 2 3 Given that the mechanism is exactly the same as for benzene, use resonance theory to explain the observed preference for substitution at the 2 position. Organic Chemistry c3046 Problem Set 1 - Electrophilic and Nucleophilic Aromatic Substitution a. b. Me NH 2 HO N O , H + NO . There is another type of electrophilic aromatic substitution called nitrosation . Provide a mechanism for this reaction. First, you must decide what is the actual electrophile here, and how it is formed. 3. NO NO E NO E E(+) (Slower than benzene) + Provide an explanation for the fact that the nitroso group (NO) is a deactivator, but an ortho/para director. Provide a mechanism for the following reaction. (The first part is an electrophilic aromatic substitution, and you need to decide what is E(+) and how it is formed.) 4. H 3 C O H 2 SO 4 CH 3 Reading: Chapter 19. Particularly relevant book problems: 19.73, 19.78, 19.83a, 19.87, 19.91, 19.96, 19.101b
description
practice problems
Transcript of Orgo PS1
O
Br
Me
Me
O EO
E
Propose syntheses of the following compounds starting from benzene and any other reagents you might need.
Electrophilic aromatic substitution is possible with aromatic systems other than benzene. For example, furan can undergo substitution to give the following products (E(+) = Electrophile):
2.
1.
E(+)+
Major Product Minor Product
23
Given that the mechanism is exactly the same as for benzene, use resonance theory toexplain the observed preference for substitution at the 2 position.
Organic Chemistry c3046Problem Set 1 - Electrophilic and Nucleophilic Aromatic Substitution
a. b. Me
NH2
HON
O, H+
NO
4.
There is another type of electrophilic aromatic substitution called nitrosation. Provide a mechanism for this reaction. First, you must decide what is the actual electrophile here, and how it is formed.
3.
NO NO
E
NO
EE(+)
(Slower than benzene)+
Provide an explanation for the fact that the nitroso group (NO) is a deactivator, but an ortho/para director.
Provide a mechanism for the following reaction. (The first part is an electrophilic aromatic substitution, and you need to decide what is E(+) and how it is formed.)
4.
H3CO
H2SO4
CH3
Reading: Chapter 19.Particularly relevant book problems: 19.73, 19.78, 19.83a, 19.87, 19.91, 19.96, 19.101b
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NCH3H3C
H3C CH3 H2SO4
NCH3H3C
C(CH3)3
5. a. Draw a mechanism for the following alkylation reaction:
+
b. To the extent that this reaction goes at all, the meta product is the major product. Why?!?
NH2
OCH3
Br
Br
Me
O
Me
Me
Cl
F
O2N
Δ
KNH2, NH3
O Na
CO2Me
Br
Br
Br
Me
Me
NH2
O
O2N
CO2Me
6.
7.
Propose syntheses for the following compounds:
from
a. b.
from
Provide detailed mechanisms for the following transformations:
a.
b.
8. Predict the product of the following reaction sequence:
1. NH3, Δ
2. NaNO2, HCl3. CuCl
