Q1 P. - Organic Chemistry (Mcmurry)

Question

What product would you expect from a nucleophilic substitution reaction of (S) -2-bromohexane with acetate ion, CH₃CO₂^- ? Assume that inversion of configuration occurs, and show the stereochemistry of both the reactant and

product.

Step-by-Step Solution

Answer

Draw the product carbon skeleton, inverting the configuration at the chirality center, and replace the leaving group (bromide) with the nucleophilic reactant (acetate).

(S)-2-bromohexane                                                     (R)-1-methylpentyl acetate

Inversion of Configuration

Inversion of configuration is a process in which the configuration of an atom is changed. If the atom in  question is a stereocenter, inversion of configuration usually changes R absolute configuration  to S, and S into R. Inversion of configuration can also convert cis into trans, or trans into cis.

Formation of product of the reactant with its Stereochemistry

By identifying the leaving group and chirality center, draw the product carbon skeleton, inverting the configuration at the chirality center, and replace the leaving group (bromide) with the nucleophilic reactant (acetate). Formation of product of the reactant with its Stereochemistry is shown below.

(S)-2-bromohexane                                                     (R)-1-methylpentyl acetate