Review Of Organic Chemistry Page 34
ADVERTISEMENT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34Organic Chemistry I Review: Highlights of Key Reactions, Mechanisms, and Principles
34
Problem: Activating or Deactivating Effect by a Newly Added Substituent. Polysubstitution
vs. Clean Monosubstitution. A thought exercise.
At Halfway Point
S
S
S
S
E
1 Electrophile
1
+ 0.0
0.5
+
0.5
+ 0.5 Electrophile
50% conversion
para-only
A = SM
A = SM
E
E
B = MonoProd
C = DoubleProd
What happens when the 2nd 50% of electrophile adds?
Activating/Deactivating Effect
Amount
Amount
Amount
Case:
If: (hypothetically)
of Added Group “E”
of A
of B
of C
Product “B” ” is much
Activating
1
more reactive than SM
0.5
0
0.5
“A”
(50%)
(0%)
(50%)
Product “B” ” is much
Deactivating
2
less reactive than SM
0
1.0
0
“A”
(0%)
(100%)
(0%)
Product “B” ” is
No Effect
3
equally reactive to SM
0.25
0.50
0.25
“A”
(25%)
(50%)
(25%)
Synthetic Planning: To make multisubstituted aromatics, choose sequence with care!
If:
Make From:
Para Disubbed
An ortho-para director (a donor)
Meta Disubbed
A meta director (a strong, deactivating withdrawer)
Ortho Disubbed
An ortho-para director and para position blocked using the
sulfonation/desulfonation trick
ADVERTISEMENT
0 votes
Related Articles
Related forms
Related Categories
Parent category: Education