Question

Structures A and are stereoisomers. They are not suprimposable and are not mirror images of one another. What best describes the relationship between A and B?

Conformers

constitutional isomers

enantiomers

diastereomers

Answer 1

Diastereoisomers

Diastereomers or diastereomers are a class of stereoisomers such that they are not superimposable but neither are mirror images of one another, ie, they are not enantiomers.

Diastereomerism occurs when two or more stereoisomers of a compound have different configurations in one or more, but not all related equivalents. Stereocenters are not mirror images of each other. When two diastereoisomers differ from each other in a single stereocenter, they are epimers. Each stereocenter gives rise to two different configurations and therefore increases the number of stereoisomers by a factor of two.

The diastereoisomers differ from the enantiomers since the latter are the pairs of stereoisomers that differ from all stereocenters and are therefore reflections of one another. The enantiomers of a compound with more than one stereocenter are also called diastereoisomers of the other stereoisomers of the compound that is not its mirror image. Diastereomers have different physical properties and different reactivity, unlike enantiomers.