Site pages
Current course
Participants
General
Topic 1
Topic 2
Topic 3
Topic 4
Topic 5
Topic 6
Topic 7
Topic 8
Topic 9
Topic 10
Topic 11
Topic 12
Topic 13
Topic 14
Topic 15
Topic 16
Topic 17
Topic 18
Topic 19
Topic 20
Topic 21
Topic 22
Topic 23
Topic 24
Topic 25
Topic 26
Topic 27
3.2.1.1.2.2 D&L isomerism
The designation of a sugar isomer as the D form or of its mirror image as the L form is determined by its spatial relationship to the parent compound of the carbohydrate family, the three carbon sugar glyceraldehydes.
The orientation of the -H and -OH groups around the carbon atom adjacent to the terminal primary alcohol carbon determines whether the sugar belongs to the D or L series. When the -OH group on this carbon is on the right, the sugar is a member of the D series; when it is on the left, it is a member of the L series. Most of the monosaccharide occurring in nature is of the D configuration.
The structure of D and L Glyceraldehyde and D and L glucose are given below:
|