The pair of reactions depicted below are

Concept:-

Stereospecific reaction:

• A reaction in which the stereochemistry of the reactants controls the outcome of the reaction.
• In general, one stereoisomer of a certain reactant produces one stereoisomer of a certain product, whereas a different stereoisomer of the same reactant produces a different stereoisomer of the same product.
• An example of a stereospecific reaction is

Stereoselective reaction:

• A stereoselective reaction occurs when more than one reaction occurs between a set of reactants under the same conditions, resulting in stereoisomers that result in greater amounts of one product than the others.
• Enantioselective reactions produce only enantiomers and are therefore stereoselective.
• An example of a stereoselective reaction is

Explanation:-

The product formed in the reaction are A and B respectively.

• The mirror image of compound A is compound C and if compound C is rotated through 180^o (in plane) it gives compound D.
• Compound D and compound B does not has any mirror image relationship.
• Thus, this two reactions are examples of diastereospecific reactions.

​Conclusion:-

Hence, the pair of reactions depicted below are diastereospecific reactions.