160
CH20H
I
C=O
I
HO-C-H }
?=O
D-threo
H-C-OH
I
CH20H
n- threo-Hexo-2,4diulose
S.3
CH20H
I
H-C-OH
I
HO-C-H
I
c=o
I
L-a/tro
c=o
I
HO-C-H
I
HO-C-H
I
CH20H
L-altro-Octo4,5-diulose
(not: L-talo)
5 Carbohydrates
CH20H
I
H-C-OH
I
c=o
I
H-C-OH
I
D-gulo
HO-C-H
I
c=o
I
H-C-OH
I
H-C-OH D-g/ycero
I
CH20H
n-glycero-n-guloNono-3,6-diulose
Ketoaldoses (Aldoketoses, Aldosuloses)
Logical extrapolation of the above procedures furnishes the systematic
... os-n-ulose names of ketoaldoses. However, dehydro names are frequently preferred in a biochemical context.
HC=O
I
HO-C-H }
I
C=O
I
D-arabino
H-C-OH
I
H-C-OH
I
CH20H
n-arabino-Hexos-3- ulose
(3-Dehydro- n-altrose)
HC=O
I
HO-C-H
I
H-C-OH
I
C = 0
L -galacto
I
H-C-OH
I
HO-C-H
I
H - C - OH D-glycero
I
CH20H
n-glycero-L-galacto-Octos-4-ulose
(4-Dehydro-n-erythro- n-altro-octose)
For the cyclic hemiacetal forms of these sugars the position of the ring -size
designator depends upon which carbonyl group participates in ring formation.