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494 Chapter 15
Copyright © 2017 Pearson Education, Inc.
46.
a.
At neutral pH, both carboxyl groups of succinic acid are in their basic form.
_
_
O
C
CH
3
O
O
O
_
O
O
O O
CH
3
_
_
C
O
CH
3
C
CH
2
CH
2
C
O
O
C
CH
3
_
O
C
CH
3
C
O
O
CH
3
C
CH
2
CH
2
C
CH
2
CH
2
C
C
O
O
CH
3
C
O
C
CH
3
_
_
O
O
O
O O
O
+
+
O
O
O
O
C
O
O
O
O
b.
Without acetic anhydride, the leaving group would be hydroxide ion. Acetic anhydride causes the reaction
to take place via two successive nucleophilic acyl substitution reactions. In both reactions, the leaving group
is acetate ion, which is much less basic than hydroxide ion and therefore a better leaving group.
47.
a.
CH
3
CH
2
OH
C
O
SOCl
2
CH
3
CH
2
Cl
C
O
CH
3
CH
2
O
C
O
OH
b.
SOCl
2
NHCH
2
CH
3
C
O
OH
C
O
Cl
2 CH
3
CH
2
NH
2
C
O