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Chapter 20 699
Copyright © 2017 Pearson Education, Inc.
71.
HC
OH
H
HO H
OH
H
OH
H
CH
2
OH
N-hemoglobin
H
2
O
+
H
2
O
+
H
HC
OH H
HO H
OH H
OH H
CH
2
OH
NH-hemoglobin
H
2
O
+
HC
C OH
HO H
OH
H
OH
H
CH
2
OH
NH-hemoglobin
H
CH
2
NH-hemoglobin
C O
HO H
OH
H
OH
H
CH
2
OH
H H
2
O
+
CH
2
NH-hemoglobin
C O
HO H
OH H
OH H
CH
2
OH
+
H
3
O
+
72.
Because all the glucose units have six-membered rings, the 5-position is never methylated.
2,3,4,6-tetra-
O
-methyl-d-glucose has only its 1-position in an acetal linkage.
2,4,6-tri-
O
-methyl-d-glucose has its 1- and 3-positions in an acetal linkage.
2,3,4-tri-
O
-methyl-d-glucose has its 1- and 6-positions in an acetal linkage.
2,4-di-
O
-methyl-d-glucose has its 1-, 3-, and 6-positions in an acetal linkage.
O
O
HO
CH
2
OH
OH
OH
OH
OH
O CH
2
O
HO
OH
O
HO
CH
2
OH
O CH
2
O
HO
OH
O
O
O
CH
2
OH
These corners are not
methylene groups;
it is a convention used
when linking Haworth
projections.
HO
O
OH
1,6 -linkage
1,3 -linkage
3,6 -linkage
1,6 -linkage