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Chapter 20 683
Copyright © 2017 Pearson Education, Inc.
19.
The hemiacetals in
a
and
b
have one asymmetric center; therefore, each has two stereoisomers. The hemi-
acetals in
c
and
b
have two asymmetric centers; therefore, each has four stereoisomers.
a.
Solved in the text.
b.
O
OH
O
OH
H
3
C
H
3
C
O
OH
O
OH
H
3
C
H
3
C
c.
O OH
H
O H
OH
d.
CH
3
CH
2
CH
2
CH
3
CH
2
CH
2
CH
3
CH
2
CH
2
CH
3
CH
2
CH
2
O
OH
O
OH
O
OH
O
OH
20.
a.
O OH
CH
2
OH
HO
OH
OH
b.
O CH
2
OH
OH
HO
HO OH
c.
O
OH
CH
2
OH
HO
OH
OH
O
HO
CH
2
OH
OH
OH
HO
D
-glucose
L
-glucose
the mirror image of -
D
-glucose
-
-
21.
O
OH
OH
OH
HO
CH
2
OH
H