diastereomeereinä

Diastereomereinä are stereoisomers that are not mirror images of each other. In a molecule with more than one chiral center, diastereomers can exist. If two molecules are stereoisomers but are not enantiomers (non-superimposable mirror images), then they must be diastereomers. This definition applies to molecules with two or more chiral centers. For molecules with only one chiral center, there are only two possible stereoisomers, which are enantiomers if they are mirror images.

A key characteristic of diastereomers is that they have different physical and chemical properties. Unlike enantiomers, which have identical physical properties (melting point, boiling point, solubility, etc.) except for their interaction with plane-polarized light, diastereomers will generally exhibit different physical properties. This difference in properties can be exploited for their separation, for example, through chromatography or fractional crystallization.

In terms of chemical reactivity, diastereomers can react differently with chiral reagents. While enantiomers react at the same rate with chiral reagents, diastereomers can react at different rates, and sometimes even with different stereochemical outcomes, due to their differing spatial arrangements. This difference in reactivity is fundamental to many stereoselective synthesis strategies.

The term "diastereomer" comes from the Greek words "dia" meaning "through" or "across" and "stereos" meaning "solid," implying a difference in the spatial arrangement of atoms. This contrasts with "enantiomer," where "enantio" means "opposite."