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528 Chapter 16
Copyright © 2017 Pearson Education, Inc.
42.
a.
OH
CH
2
OH
b.
NaBH
4
both groups would
be reduced
because it is not strong enough a reducing agent to
reduce the less reactive ester
43.
An acetal has a very poor leaving group
1
CH
3
O
-
2
.
CH
3
C H
OCH
3
OCH
3
44.
If the OH group of the carboxylic acid is not protected, both OH groups will be converted to COOH
groups.
_
HO
OH
O
pyridine
SOCl
2
Cl
Cl
O
C N
C
C
O
N
N
H
2
O HCl
HOOC
COOH
O
45.
If the yield of each step is 80
%
, the yield of
B
is 80
%
; the yield of
C
from
B
is 80
%
times the yield of
B
;
the yield of
D
from
C
is 80
%
times the yield of
C
; and so on.
a.
A
B
C
D
E
F
G
80%
0.80
×
0.80
0.80
×
0.64
0.80
×
0.51
0.80
×
0.41
0.80
×
0.33
64%
51%
41%
33%
26%
b.
G
H
I
26%
0.80 × 0.26
0.80 × 0.21
21%
17%