Chapter 15.7, Problem 18ATS

Interpretation Introduction

Interpretation:

The products for the given reaction under given condition and their differentiation between products should be determined using IR spectroscopy.

Concept Introduction:

IR spectral studies: It is a spectroscopic technique which is used to determine the functional groups present in the given compound sample by absorbing frequency in particular range with respect to the group present in the given sample.

Wavenumber: It is defined as the number of waves in one centimeter. The wavenumber indicates the location of each signal with respect to the functional group in the molecule and its unit is ${\text{cm}}^{\text{-1}}$.

Elimination Reaction: It is just reverse reaction of addition where substituent from the given molecule is removed via E1 (the reaction depends only on the substrate involved in the reaction) or E2 (the reaction depends on both of the substituents in the reaction) mechanism.

In an elimination reaction, alkenes are formed when alkyl halides are treated with bases via eliminating one β-proton and one α-halo group of the alkyl halide.

The product of the elimination reaction depends on β-positions of alkyl halide.

Substitution Reaction: The reaction in which one group gets substituted by other group. The types of substitution reactions are electrophilic and nucleophilic substitution reactions.

${\text{S}}_{\text{N}}2$Reaction: It is a nucleophilic substitution reaction in which the rate determining step depends on both of the molecules involved. The bond making and the bond breaking process happens simultaneously in this reaction which results the product with inversed configuration with respect to the reactant.

Structure of the substrate plays major role in the reactivity of ${\text{S}}_{\text{N}}2$ reaction. Primary substrate favors ${\text{S}}_{\text{N}}2$ reaction.

Leaving group: It is a fragment that leaves substrate with a pair of electrons via heterolytic bond cleavage.

Nucleophile: Donates pair of electrons to positively charged substrate resulting in the formation of chemical bond.

To determine: The products and the signals used to distinguish the products formed.