Dextrose skrev:
Pharm skrev:
Diastereomere er kun hvis molekylet har 2 eller flere chirale centre. Det har DOI ikke, så de kan højst blive enantiomere

Okay, jeg troede netop at det var en diastereomer netop fordi der kun er ét kiralt center
Det er følgende quote fra wikipedia der har forvirret mig lidt:
http://en.wikipedia.org/wiki/Diastereomers skrev:
Diastereomers are stereoisomers that are not enantiomers, or mirror images of each other. Diastereomers can have different physical properties and different reactivity.
In simple terms two stereoisomers are said to be diastereoisomers of each other if only one chiral center differs between the two stereoisomers.
Hvis du har et molekyle med ét chiralt center, kan den ene være S-form og den anden R-form.
Et molekyle med to chirale centre kan da så hedde enten (S,R) (S,S) (R,S) og (R,R) dvs. der findes 4 stereoisomere (n^2 reglen). To molekyler hvor det ene har (R,S) konfiguration og det andet (S,R) konfiguration siges at være diastereomere.
Fra min organisk kemibog:
Citat:
Diastereomers are stereoisomeres that are not mirror images. They are similiar, but they are not identical and they aren't mirror images. Enantiomers have opposite configurations at all stereocenters; diastereomers have opposite configurations at some (one or more) stereocenters, but the same configuration at others.