Differentiate between retention and inversion.
Hint:When a nucleophile approaches the chiral carbon from the same side as the leaving group, it results in retention of configuration. Conversely, when the nucleophile attacks the chiral carbon from the opposite side of the leaving group, it leads to an inversion of configuration.
|
Retention |
Inversion |
| Retention is described as a condition where the absolute and relative configurations of an atom or molecule remain unchanged. | Inversion refers to a state where the absolute and relative configurations of an atom or molecule are altered. During inversion of configuration, the chiral carbon and the group attached to it shift positions in the reaction, resulting in a product that differs in structure from the reactant. |
| In retention of configuration, the chiral carbon and the group bonded to it stay in the same orientation before and after the reaction. | In inversion, the nucleophile attacks from the opposite side (backside attack), while in retention, the nucleophile approaches from the same side (frontside attack). |
| Retention in configuration keeps the R-configuration of a compound as R, and the S-configuration as S. | Inversion of configuration alters the R-configuration of a compound to S, and the S-configuration to R. |
Note: The nucleophilic substitution reaction that adheres to the…SN2 type of mechanism shows inversion of configuration. In nucleophilic substitution reactions which follow SN1type of mechanism, a racemic mixture is formed out of which one product shows retention in configuration and another product shows inversion of configuration.