Chapter 8, Problem 8.11P

Interpretation Introduction

Interpretation:

The complete and detailed mechanism and products for an ${\text{S}}_{\text{N}}\text{1}$ reaction between the given reactants are to be drawn. It is to be determined if the reaction will produce a single stereoisomer or a mixture of stereoisomers. If it produces a mixture, then it is to be determined if those isomers will be produced in equal amounts.

Concept introduction:

An ${\text{S}}_{\text{N}}\text{1}$ reaction is a two-step reaction. A carbocation is formed in the first reaction as a result of the leaving group breaking off, taking its bond pair with the carbon atom. The incoming nucleophile attacks the carbocation in the second step, forming the product.

The carbocation intermediate formed in ${\text{S}}_{\text{N}}\text{1}$ reaction is ${\text{sp}}^{\text{2}}$ hybridized, and its molecular geometry is trigonal planar. This geometry creates two different sites for the nucleophilic attack. The formation of stereoisomers depends on the stereochemical nature of the given reactant. If a chiral center is generated in a single elementary step from an atom that is not a chiral center, then both R and S configurations will be produced. If a new chiral center is produced in an elementary step, then the R and S configurations of the chiral centers are produced in equal amounts if the reactants and the environment are achiral or in unequal amounts if the reactants or the environment are chiral.